- hace 10 minutos
The Japanese city of Kobe is rocked by the Great Hanshin earthquake, which destroys many of its buildings. Many traditional houses collapse due to the heavy roofs and weak walls. Soil liquefaction occurs at the coastal and port areas of Kobe. 6,434 people die in what is then Japan's worst peacetime disaster.
Categoría
📺
TVTranscripción
00:00Kobe, Japan's sixth largest city and one of its most important commercial centers.
00:07Then, one quiet winter's morning, just before dawn, disaster strikes.
00:12Suddenly, without warning, a colossal earthquake rips through the city.
00:17It topples roadways and knocks over tower blocks.
00:21In 20 seconds, Kobe is left in ruins.
00:24Over 5,500 people die.
00:27Now, using advanced computer simulations, we reveal exactly why so many died in what was meant to be the most
00:34earthquake-proof country on Earth.
00:37Behind every disaster lies a chain of critical events that decide who lives and who dies.
00:44Unravel the clues and count down those final seconds from disaster.
00:56Asia.
00:58Japan.
01:01Kobe.
01:04Home to nearly one and a half million people, Kobe is famous for its breathtaking views.
01:09But land here is at a premium.
01:13Kobe is squeezed between the Rocco Mountains and the blue waters of Osaka Bay.
01:19The city center sits on a narrow strip of land just five kilometers wide.
01:24To the east and west lie densely populated residential areas of mostly traditional houses.
01:30And to the south, its huge port area, built on a series of islands created by dumping millions of tons
01:37of soil into the sea.
01:40It's one of the world's biggest ports, handling $71 billion of cargo a year.
01:46To maximize precious space, 160 kilometers of Kobe's modern freeway system stand on pillars above the city.
01:56Monday, January 16th, 1995.
02:01It's a bright winter's day, the temperature just above freezing.
02:05Today is a national holiday and Kobe bustles with people soaking up the holiday atmosphere.
02:13But beneath their feet, the ground is riddled with faults.
02:17These unstable cracks in the earth, 20 kilometers below the ground, are caused by movements of the earth's surface.
02:24Japan is one of the world's most active earthquake zones.
02:28In Kobe, these faults stretch the length of the city center along the foot of the mountains.
02:34But Kobe is lucky. Fault activity is rare here.
02:38The city hasn't seen a major quake in 400 years.
02:44Ten kilometers east of the center is the residential area of Higashinada.
02:49Most of the houses here are of traditional Japanese design with a wooden frame and ornate roof tiles.
02:56In one of them, built 50 years ago, lives 59-year-old Yukiko Shona.
03:00She shares her home with her son Satoshi and her dog.
03:05Her five-year-old granddaughter is staying with them for the holiday.
03:11Yukiko has lived in Kobe all her life.
03:14Her sole experience of earthquakes is just a couple of minor tremors.
03:21Earthquakes were something tiny. I can't even recall anything falling from the shelves.
03:26So I didn't think earthquakes were anything to be scared of.
03:3330 kilometers east of Kobe is the Osaka Earthquake Observatory.
03:39Here, scientists monitor part of a network of thousands of seismic sensors spread all over Japan.
03:46Tonight, Toshio Arimoto is on duty with a colleague.
03:51In 21 years, he's monitored several major earthquakes across the country.
03:56But today, doesn't feel like a proper work day.
04:01Because it was a public holiday, I really felt like it was a day off.
04:05And I wasn't expecting anything unusual at all.
04:116.26 p.m.
04:14Their quiet shift is suddenly interrupted.
04:17An earth tremor measuring 3.6 on the Richter scale triggers the sensor network.
04:25And this one's tiny. Too small even to rattle the windows.
04:3623 minutes later, ground shaking triggers the sensor network again.
04:41But this tremor is smaller still, measuring just 2.5.
04:47The sensors reveal that the tremors originate beneath the Akashi Channel,
04:51which separates Awaji Island from the mainland.
04:55It's 15 kilometers southwest of Kobe.
04:59In Kobe City, people are oblivious to the tremors.
05:08Shinchu, 400 kilometers northeast of Kobe.
05:13Tour bus driver Yoshio Fukumoto leaves town, heading south.
05:19He's been driving buses for 30 years.
05:25I like driving.
05:26And in those days, it was cool to be a tourist bus driver.
05:29So I really enjoyed it.
05:36Fukumoto's destination is Kobe.
05:38It's an overnight trip scheduled to take 12 hours.
05:496.55 p.m.
05:51A third tremor.
05:52This one, a 1.5 p.m.
05:54The scientists are surprised to see three tremors in a matter of minutes.
05:57But Arimoto is still not alarmed.
06:03From the local seismic activity at the time,
06:05it really was unimaginable that a huge earthquake could occur in Kobe.
06:13In Yukiko Shono's home in Kobe, her granddaughter develops a fever.
06:20Yukiko rings her daughter, who agrees that the little girl should go home.
06:26Yukiko will not have her granddaughter staying with her tonight.
06:3411.49 p.m.
06:37After nearly five hours of silence, a fourth tremor shakes the Akashi channel.
06:42On average, there are five tremors exceeding magnitude 1.5 in a year.
06:46There have now been four in just under five and a half hours.
06:5329-year-old Satoshi Shono keeps his mother Yukiko up past her bedtime.
06:57He's keen to show her his latest gadget, a laptop computer.
07:05We stayed up chatting for quite a while that evening.
07:09Then it turned midnight and he said,
07:11You should go to bed, Mum.
07:12I'll have to stay up until about 2.
07:15Good night.
07:20Tuesday, January 17th, 5.45 a.m.
07:25Tour bus driver Yoshio Fukumoto is just 15 kilometres from the centre of Kobe.
07:31Just three passengers remain on board.
07:36He's on the Hanshin Expressway,
07:38a 40-kilometer-long four-lane elevated freeway that runs right through Kobe.
07:44It's designed to be earthquake-proof,
07:47but like the rest of the city, it's never been put to the test.
07:52Fukumoto soon expects to be heading back to his family in nearby Kyoto.
08:02But then, after nearly six hours of inactivity,
08:05the ground beneath the Akashi Channel begins to move again,
08:09triggering the sensors in the earthquake observatory in Osaka.
08:12This time, it's more than just a tremor.
08:23January 17th, 1995.
08:265.46 a.m.
08:30Of the fire station on Port Island in the Japanese city of Kobe,
08:33firefighter Makoto Fuji works the early shift.
08:37He's been on duty at the station for over 20 hours.
08:44In a little under four hours' time, he'll be heading home to his wife.
08:495.46 and 58 seconds.
08:52Fukumoto's routine journey takes an unexpected turn.
08:56Everything begins to shake violently.
09:04The freeway started to weave.
09:07I'd seen something like this in the movies,
09:09but I never thought I'd see the real thing.
09:13It's like driving on waves.
09:16I couldn't see properly.
09:17Couldn't focus because of the bouncing.
09:19I don't know.
09:21I don't know.
09:234.5 kilometers west of Fukumoto's bus,
09:2759-year-old grandmother Yukiko Shono wakes suddenly
09:30as the ground trembles beneath her house.
09:34At first, it shook like this.
09:37And I thought, it's an earthquake, a strong one.
09:41And then it stopped.
09:42And I thought, okay, it's just a tiny tremor.
09:46For a second, everything seems fine.
09:50It seems really weird.
09:52But there wasn't any sound.
09:55Then, Yukiko Shono's world turns upside down.
10:12At the Port Island fire station, the earth begins to shake.
10:22It went right through my body.
10:24It felt as though the building would tear itself apart.
10:31The chairs and things on the desk crash to the floor.
10:36Kobe is in the grip of a massive earthquake.
10:39A security camera at the regional office of TV channel NHK
10:43captures the violent shaking.
10:45It wakes a technician asleep on a camp bed.
10:4918 kilometers away, on the swaying freeway,
10:52Fukumoto's bus could go right through the barriers and over the edge.
10:56He slams on the brakes.
10:58But just when the danger seems past, the road begins to move again.
11:04I pulled on the handbrake, and at that moment, the road in front of me just fell away.
11:13I really thought we'd fallen off the edge.
11:19I was paralyzed with fear.
11:23At the Port Island fire station, Nakoto Fuji looks outside.
11:28He sees something incredible.
11:30A flood of water spurts up through gaping cracks in the ground.
11:38I didn't know what to think.
11:42Maybe this is a crack and the island is going to split in two.
11:47Or maybe it was a big water pipe that had broken under the ground.
11:51I just couldn't work it out.
11:5630 kilometers away, in the Osaka Observatory, Toshio Arimoto races to find the origin of the quake.
12:05It read, Awaji Island, magnitude 7.2.
12:10Awaji Island sits on the edge of the Akashi Channel, just 15 kilometers from Kobe City.
12:15Arimoto is staggered.
12:17For the first time in four centuries, a massive earthquake has struck the Kobe area.
12:265.47 and 12 seconds.
12:29Just 14 seconds after the violent shuddering began, the earthquake subsides.
12:35Yoshio Fukumoto holds his breath.
12:37His bust teeters on the edge of the shattered freeway.
12:40The front wheels hang over a 15-meter drop.
12:44He's terrified that it will plunge to the ground.
12:47He must get the passengers off the bus.
12:58Yukiko Shono, trapped in the rubble of her home, gradually regains consciousness.
13:03But she's so dazed, she doesn't even realize where she is.
13:09I felt pain, as though my whole body had been shattered.
13:13I thought I had had a car accident, got hit by a car, and my body was paralyzed.
13:19That's what I thought, it was a car accident.
13:26Now in Kobe's residential areas, there's a deadly new hazard.
13:31Fire.
13:32Hundreds lie trapped in the collapsed remains of their traditional wooden houses.
13:38Dawn light reveals the vast scale of the disaster.
13:41The quake knocked tower blocks to the ground.
13:46Toppled road bridges and flattened entire neighborhoods of traditional Japanese houses.
13:53Thousands of people lie dead and dying in the city's shattered remains.
13:59Under her crushed house, Yukiko Shono lies trapped and badly injured.
14:05The temperature is just above freezing.
14:08If rescuers don't come soon, the alternatives are grim.
14:12Freeze to death.
14:13Or be burnt alive.
14:20A magnitude 7.2 earthquake rips apart the Japanese city of Kobe.
14:25Thousands lie trapped and dying under wreckage.
14:29On the Hanshin Expressway, a tour bus narrowly escapes disaster.
14:34After getting his passengers safely off the bus,
14:37driver Yoshio Fukumoto is desperate to tell his company in Kyoto what's happened.
14:45So I phoned the office and said,
14:46the Hanshin Expressway has collapsed.
14:48The bus is just hanging off the edge.
14:54He told me to stop joking.
14:56Maybe it was a bit too early in the morning for him, but he sounded annoyed.
15:03The man tells Yoshio to go back and retrieve the bus's legal documents,
15:07in case the bus falls over the edge.
15:13The guy just didn't understand what had happened.
15:20It was hard to believe.
15:26Dutifully, Yoshio returns to the precariously balanced bus.
15:30He inches towards the front and retrieves the documents.
15:38In the dawn light, Fukumoto takes pictures of his remarkable escape,
15:42using a disposable camera.
15:46The way it was sticking out looked completely different from when we were up there.
15:50It was much more scared to look up from beneath.
15:53And I really wondered how I'd survived.
15:59It's a miraculous escape.
16:02Fukumoto walks away from his brush with death, without a scratch.
16:104.5 kilometres from the stranded bus, 59-year-old Yukiko Shono isn't so lucky.
16:16She's been crushed beneath the wreckage of her home for over two hours.
16:24I couldn't breathe, and I was choking and sweating.
16:27I thought the only release from this agony would be to die.
16:31I wondered how I could kill myself.
16:38Kobe's emergency services struggle to cope with the scale of the disaster.
16:49Emergency vehicles find it almost impossible to move around the city's debris-clogged streets.
16:578.30 a.m.
17:00Yukiko's daughter Kumiko arrives in her mother's traditional neighbourhood with her husband.
17:05Her own more modern home survived the quake.
17:08She and her little daughter escaped unhurt.
17:12But she's horrified to find that where her mother's house stood is just a shattered pile of timber and roof
17:19tiles.
17:20She realises her mother and brother must lie beneath the tons of debris.
17:26At that point I thought they were probably dead, because I couldn't believe a person could survive under that rubble.
17:37Ruptured gas mains fuel fires raging across the city.
17:46But the quake also breaks many of the water mains, leaving firefighters helpless in the face of the inferno.
17:52They pump water straight from the sea, but it's a frustratingly slow process.
18:00There was no water, and having no water at the fire was deadly.
18:07I just felt really helpless.
18:09Everything I had learnt before was no use at all in the earthquake.
18:172.30 p.m.
18:18In the region where Yukiko Shono lives, many of the traditional wooden houses are ablaze.
18:24And the fires are spreading.
18:26She becomes increasingly desperate.
18:29I was in such agony.
18:31I couldn't move my right arm at all because it was trapped.
18:34But I found this piece of wood.
18:37With my left hand I started to make a banging noise.
18:45Outside, Yukiko's daughter hears something.
18:48It's not her mother, but her mother's dog.
18:53Komiko is certain the dog is trying to tell her something.
19:02She barked and stopped, barked and stopped, and kept staring at my face.
19:08Then she barks again, and when she stops, I can hear a tapping noise.
19:17So I called out, mother, mother, and we heard a tapping response.
19:22And we realized she was still alive.
19:28Komiko finds some construction workers.
19:31They help her dig towards the sounds of the tapping.
19:41It's slow work.
19:42One wrong move, and the wreckage could crash down and kill her mother.
19:52Two hours later, they finally reach Yukiko.
19:56She's been buried for 10 hours.
19:58Her right leg is paralyzed.
20:00Her hip is broken.
20:02But she is alive.
20:11Finding her mother gives Komiko new hope.
20:14Her younger brother, Satoshi, could be alive too, somewhere under the debris.
20:20She calls out, but he doesn't answer.
20:24They start to dig again.
20:30Five hours later, they find him.
20:33But it's too late.
20:41When they checked my brother's pulse, they told me he didn't make it.
20:54It was the most shocking thing that's ever happened to me.
20:58That evening, Komiko has to break it to her mother that her beloved son is dead.
21:03He was just 29 years old.
21:07So my daughter told me that Satoshi didn't make it.
21:10And I couldn't speak.
21:13I just said,
21:16I see.
21:20I cried underneath my quilt after she left,
21:23making sure that my tears couldn't be seen from the outside.
21:30Yukiko Shono's son is just one of 5,502 people killed.
21:36More than 235,000 people are homeless.
21:39More than 100,000 buildings destroyed.
21:42The quake wrecks electricity and water systems.
21:47The damage tops $150 billion.
21:50It's the world's most costly disaster.
21:53It overwhelmed the city's emergency services.
21:56And help from the national government took almost two days to arrive.
22:03Japan prides itself on its ability to build earthquake-proof buildings.
22:07So why does their city lie in ruins?
22:10And why didn't scientists predict a major quake?
22:15The population of Kobe wants answers.
22:2124 separate teams of experts embark on a wide-ranging investigation of the disaster.
22:28Seismologists will explore the quake itself,
22:30while engineering experts probe the failure of buildings and structures.
22:35Now, by rewinding the disaster and by going deep into the investigation,
22:40we reveal what really happened at Kobe.
22:43How so many people died,
22:44and why the quake left the city looking like a war zone.
22:48Advanced computer simulation will take us where no camera can go,
22:52into the heart of the Kobe disaster.
23:03Earthquake expert Professor Charles Scorthorne is one of the first on the scene.
23:07By a remarkable coincidence,
23:09he was attending an earthquake conference just 30 kilometers from Kobe,
23:13and actually felt the quake.
23:15He quickly realizes that this is an earthquake of colossal proportions.
23:21This was the most significant earthquake of the second half of the 20th century.
23:25This was a direct hit on as modern a society as you can have in the world,
23:31and it was totally devastated.
23:37Japanese experts working with him cannot believe the scale of the destruction.
23:42My Japanese colleagues really were having a difficult time,
23:46because they just did not expect this.
23:50It may be like Americans on 9-11.
23:52This was something that was shocking.
24:01Earthquakes are a fact of life in Japan.
24:03Thirteen major quakes have hit the country in the last 100 years,
24:07killing over 150,000 people.
24:11The country sits on the boundaries of four massive tectonic plates.
24:18As these plates shift, the movement triggers quakes along a network of thousands of fault lines under Japan.
24:26Kobe lies 200 kilometers north of the nearest plate boundary, called the Nankai Trough.
24:32So major quakes in the region are very rare.
24:35But this time, tectonic movement at this boundary is big enough to reach Kobe.
24:40Seismic equipment reveals that the quake is magnitude 7.2,
24:45powerful enough to be picked up by sensors on the other side of the planet.
24:50The quake scores a direct hit on Kobe City.
24:53But scientists are puzzled to find that its original epicenter is 15 kilometers away.
25:01It doesn't seem to make any sense.
25:04This should put Kobe outside the zone of severe damage.
25:08So what did cause the destruction in Kobe City?
25:15The quake's epicenter is under Awaji Island in a fault well known to seismologists.
25:20But a quake here should only cause serious damage in Awaji.
25:25It cannot explain the scale of the devastation 15 kilometers away in Kobe.
25:30This could only be caused by a fault rupturing directly under the city.
25:38Experts analyze hundreds of sensor readings from the Kobe quake and discover a shocking fact.
25:44There's a subterranean fault line beneath the Akashi channel that scientists were completely unaware of.
25:51Previous surveys didn't pick it up.
25:54It's not large, but it links the Awaji fault to a fault directly under Kobe.
26:05January 16th, 11.49pm.
26:08The series of small quakes that Toshio Arimoto sees in the Osaka Earthquake Observatory are not just harmless tremors.
26:16It's the ground on either side of the fault line beginning to shift 15 kilometers beneath the surface of Awaji
26:23Island.
26:245.46am and 52 seconds.
26:27Scientists are now certain that the violence of the Awaji earthquake triggers a chain reaction through the undiscovered fault.
26:35The quake now races along this fault towards Kobe at 9,000 kilometers per hour.
26:41Six seconds later, the fault under the city ruptures. It's a direct hit.
26:51The earthquake goes off with the energy of a 65 kiloton nuclear bomb.
26:59Even if Arimoto had known about the undiscovered fault line, the initial tremors don't necessarily indicate that a quake is
27:07imminent.
27:11I suppose if you look at it afterwards, you could see it as a foreshock.
27:20But there's no way to predict there's going to be a huge disaster from just observing a bunch of tremors.
27:33Even today, it remains impossible to predict an earthquake.
27:39It's clear how the quake scores a direct hit on Kobe.
27:44Now investigators must focus on another puzzle.
27:48Why did more than 5,000 people die in the disaster in a country that's renowned for building earthquake-proof
27:55cities?
27:59When investigators analyze the pattern of fatalities, they discover that the overwhelming majority of deaths occur in the city suburbs.
28:09Here, whole streets of traditional timber-framed Japanese houses simply collapse.
28:154,900 of the quake's victims die in this type of house.
28:21The investigators' first priority is to find out why.
28:26They examine the design.
28:29They find that these types of houses are simply constructed using a series of timber supports.
28:36But, topping this lightweight structure is an ornate tiled roof.
28:42A Japanese house has a heavy roof, so you're supporting tons of roofing on, really, just little spindly columns.
28:54One of these roofs weighs two tons.
29:00In a modern timber house, solid walls help to brace the wooden supports.
29:04But, investigators discover that walls in these older houses are made of plaster and bamboo, which have no structural strength.
29:14The unbraced posts provide the only support for the heavy roof.
29:19When the earthquake strikes, there is nothing to stop the structure swaying and then caving in.
29:26It's called a pancake collapse.
29:30As the heavy roof pancakes down, it crushes the floors below, and anyone unfortunate enough to be inside.
29:42It causes nearly nine out of ten of the deaths in Kobe.
29:47What killed everyone in Kobe, almost everyone, was the Japanese house.
29:51And the Japanese house is a killer.
29:54But, if the structure is so weak, why top them with such heavy roofs?
29:59The investigators discover an appalling irony.
30:03The heavy roofs are built to resist a natural disaster.
30:06Not earthquakes,
30:09but typhoons.
30:12On average,
30:13Kobe is hit by more than two of these destructive tropical storms every year.
30:225.46 and 58 seconds.
30:26Yukiko Shono's typhoon-proof house is no match for the devastating power of the Kobe quake.
30:34The house simply collapses, crushing her and killing her son.
30:40The heavy roofs, the very feature that might save lives in a typhoon, prove a death sentence in an earthquake.
30:51While the death toll is highest in the traditionally built suburbs, investigators find ample evidence of severe structural damage elsewhere
30:59in Kobe city.
31:02And investigators are puzzled why so many of Kobe's modern structures also collapse.
31:08These should be constructed to building codes specifically designed to withstand a major earthquake.
31:21There is no more potent symbol of this failure than the collapsed Route 3 of the Hanshin Expressway.
31:27It's 40 kilometers long, elevated above ground level by hundreds of concrete pillars.
31:33The quake damages or destroys over half of them.
31:36It also topples 26 of its 1,304 sections of roadway.
31:43Built in 1969, it was a key transport artery carrying more than 180,000 cars a day.
31:51Its loss cripples Kobe's transport system.
31:55The Japanese Ministry of Construction orders an investigation.
32:01Engineer Hirokazu Emora is one of the principal investigators.
32:05The amount of damage, astounding.
32:10Honestly speaking, we did not expect such a total collapse of the bridges.
32:16Because we design bridges with the highest seismic force in the world.
32:21So we had been thinking that our structure is the strongest.
32:28Emora and the team are mystified.
32:31The Hanshin was designed to withstand a magnitude 8.1 earthquake.
32:3522 times as powerful as the magnitude 7.2 quake that decimates it.
32:40The public clamors for answers.
32:43Were corners cut during the Hanshin's construction?
32:47The first criticism we heard from the citizens is there could have been mistakes made in the construction.
32:57Emora knows that Japanese civil engineering is under the microscope.
33:03We wanted to show citizens that we did not make any mistakes in the construction.
33:12The team begins a forensic examination.
33:14One of the key failures is in the eastern suburbs, where Yoshio Fukumoto's bus had a lucky escape.
33:24A whole section of roadway has simply fallen off its pillar.
33:28It leaves the bus teetering on the very edge of a 15-meter drop.
33:36Investigators know this should not be possible.
33:38Each 52-meter-long section is securely bolted to the pillars by cast-iron fixings 190 millimeters thick.
33:47But when they check the fixings, they discover that the earthquake's violence has sheared them apart.
33:55It leaves the slabs of road resting loosely on top of the pillars.
34:00But the team still can't understand why the sections of road fall.
34:04A single 965-ton slab, like the one beneath Fukumoto's bus, would have to slide 120 centimeters to drop off
34:12its pillar.
34:13They're convinced that the earthquake alone could not cause such extreme movement.
34:17In a moment, Emura and the team re-inspect the road sections.
34:21Then, on the faces of the 33-millimeter thick steel girders that support the roadway, they spot something.
34:29The thick steel has been smashed and bent.
34:33The investigators realize this damage is caused by the 965-ton girders crashing into each other.
34:41These violent impacts act like gigantic hammer blows that force the slabs of road over the edge.
34:495.46 and 58 seconds.
34:51As the quake begins, the steel fixings supporting the slabs of road snap.
34:57The sliding slabs crash together, pushing one another across the tops of the pillars.
35:04Fukumoto is now driving on a road surface that slides back and forth beneath his bus.
35:15Fukumoto screeches to a halt.
35:18His front wheels rest on a road section, teetering on the edge of its pillar.
35:22Then it slips the last few centimeters and crashes over the edge.
35:30If Fukumoto had stopped a few meters further on, his bus would have plummeted 15 meters.
35:37Chances of survival would have been slim.
35:42The way it was ticking out, I really wondered how we survived.
35:55But Fukumoto and his passengers are even luckier than they thought.
36:00Had the quake happened just minutes later, he would have traveled 4.5 kilometers further along the Hanshin.
36:06Here, the quake topples a stretch of roadway more than half a kilometer long.
36:11And it looks almost like a giant Giles toy that's laid off on its side.
36:15The girder fixings here are intact.
36:19This time, the quake has fractured the concrete pillars themselves.
36:22How did they fail?
36:26Imura and the team inspect the pillars.
36:28They find that three layers of steel bars reinforce them.
36:33It's a routine building technique.
36:36The two outer layers run all the way from top to bottom.
36:39But the inner layer stops 1.5 meters above ground level.
36:45Photographs taken during the investigation show these shorter bars sticking out of the shattered concrete.
36:51This is exactly where the pillars fail.
37:00As the ground shakes, the roadway begins to sway.
37:04Its vast weight puts immense stress on the pillars.
37:09Seconds later, the pillars snap at their weakest point, where the inner layer of reinforcing bars ends.
37:15The heavy roadway crashes to the ground.
37:20Investigators work out that if the inner reinforcing bars had not been made short like this, the Hanshin might have
37:27survived the quake.
37:32It's clear that major elements of the Hanshin structure were highly vulnerable.
37:37But it was built to strict building codes introduced in 1964.
37:42Codes that should have ensured it could withstand a much bigger quake.
37:46So why did they fail?
37:48Sensor data reveals that the epicenter was unusually shallow, just 15 kilometers below the surface.
37:55That made the ground acceleration, the violence of the movement, especially severe.
38:00But in 1964, experts had very little data on this phenomenon.
38:05Investigators discover that the ground acceleration in the Kobe quake was more than twice as violent as the 1964 building
38:13codes allowed for.
38:18It's this that causes such severe damage to the Hanshin and so many of Kobe's other modern structures.
38:25Now we knew from the results that the design method at the time was not correct.
38:34The Japanese government updated the codes three times after the Hanshin was built.
38:39But the new rules only applied to new structures, not existing ones.
38:50Investigators are starting to find out why the Kobe quake is so devastating and so deadly.
38:58How traditional Japanese houses are a death sentence for thousands.
39:02Why so many modern structures are annihilated.
39:06And how the quake scores a direct hit on the city, leaving its citizens seconds from disaster.
39:2020 seconds from disaster.
39:23An earthquake strikes the northern tip of Owaichi Island.
39:26It tears open a previously unknown fault nearby.
39:30Now the quake races along the fault at 9,000 kilometers per hour and heads straight for Kobe.
39:3714 seconds to disaster.
39:40The fault right under the city ruptures with cataclysmic force.
39:46It shakes the Hanshin Expressway like a rag doll.
39:49Still fixing sheer and whole sections of the road crash to the ground.
39:53It leaves Fukumoto's bus hanging over an abyss.
39:574.5 kilometers away, it snaps inadequately reinforced concrete pillars, downing over half a kilometer of roadway.
40:05And in hundreds of traditional houses to the east and west, it kills nearly 5,000 people as their heavy
40:12roofs crash down on top of them.
40:17Just 20 seconds after the first seismic activity, the earthquake subsides.
40:25It leaves the city of Kobe a shattered, blazing ruin.
40:32But the investigators have one puzzle still to solve.
40:36What caused the widespread subsidence in the devastated port area?
40:45Could the mysterious eruptions of muddy water reported by witnesses be a crucial clue?
40:56The Kobe quake savages the city's economy.
41:01The worst impact is felt in Kobe's vital docks area.
41:06It's so badly damaged, it's out of action for over two years, wiping out some 40 billion dollars of Kobe's
41:12vital trade.
41:17Investigators find that the damage here looks different from the rest of the city.
41:22In places the ground has dramatically subsided.
41:26And 9 kilometers of concrete dockside has fallen into the sea.
41:33Investigators learn that eyewitnesses like firefighter Makoto Fuji report a flood of water during the quake.
41:40Not from the sea, but erupting out of the ground.
41:45It was about a meter high and maybe 10 meters wide.
41:49At first, when I saw the wall of water bursting through the ground, I didn't know what to think.
41:56It's a crucial clue.
41:58Investigators suspect that Fuji witnessed an unusual phenomenon that can be caused by major quakes.
42:07Niigata in North Central Japan, 1964.
42:10This original film shows a slurry of muddy water erupting out of the ground during a quake.
42:16It was the first time this phenomenon had been captured on film.
42:24It undermines the foundations of buildings, causing severe damage.
42:29The phenomenon is now known as liquefaction.
42:31It happens when a quake strikes ground saturated with water.
42:35Just like the land beneath Kobe's Port Island.
42:41Port Island is built on land reclaimed from the sea in Kobe's harbor.
42:44City authorities dumped 80 million cubic meters of sandy soil from the Rocco Mountains over an area of 4.5
42:52square kilometers.
42:53The 14-year project was completed in 1980.
42:57The land-filled area would usually be a perfectly reliable base for buildings.
43:02But, just below the surface, it's loosely packed and saturated with water.
43:135.46 a.m. and 58 seconds.
43:17When the earthquake strikes, the shock waves shake Port Island's loose, sandy soil.
43:24If you take a can of coffee, coffee grounds, and you tap it, you know the coffee grounds will settle.
43:31Well, sand is very much the same way.
43:33And if the earthquake taps it, that ground will settle.
43:37The gaps between the loosely packed sand grains are filled with water.
43:42The quake compacts the grains tightly, forcing the water up towards the surface under terrific pressure.
43:50What Fuji sees is not a broken water main, but a flood of liquefied soil.
43:58Investigators conclude that wide-scale liquefaction of reclaimed land is what destroys much of Kobe's Port.
44:12In the wake of the disaster, city authorities rebuild Kobe using the latest earthquake-proofing technology.
44:18They spend $6.8 billion on the Port alone, rebuilding the dock walls with much deeper foundations to resist any
44:26future quake.
44:27Modern houses with solid walls and light roofs replace the flattened neighborhoods of traditional homes.
44:32And the elevated expressways get a $3 billion upgrade, with more reinforcing bars and steel sheathing on the columns.
44:44Yoshio Fukumoto still drives buses.
44:47His lucky escape made him Japan's most famous bus driver.
44:50But news of earthquakes still sends chills down his spine.
44:59When I see earthquakes today, I feel a raw pain.
45:05I'm very frightened of earthquakes.
45:12Yukiko Shono still lives in Kobe, on the site of the house where her son Satoshi died.
45:24Yukiko now gives public talks, advising people how to be prepared if an earthquake strikes.
45:33If that saves even one more life, the next disaster, this is the least I can do for those who
45:40died.
45:43If there is a world beyond this one, when I get to where my son is, I can at least
45:50smile and proudly tell him,
45:53Mummy has done well.
45:58After the Kobe disaster, Japan's government introduced a national disaster strategy to ensure fast response by rescuers and equipment in
46:07the event of a major quake.
46:10When a magnitude 6.8 quake hit the city of Nagata in 2004, special rescue teams were on the scene
46:17within hours.
46:19The Kobe disaster forced the Japanese to reappraise just how earthquake-proof their cities really are.
46:25They can't change their earthquake-prone country, but the lessons learned from Kobe will save thousands of lives when another
46:32major earthquake strikes.
Comentarios