A 44-year-old building came tumbling down in seconds on Sunday, March 25, to make way for a new skyscraper in downtown Austin.Around 400 pounds of explosives were used to bring down the 10-story Ashbel Smith Hall, which was once the administrative offices for the University of Texas, according to the Austin Fire Department.A 36-story, 670,000-square-foot mixed-use building will take its place and is expected to become the tallest building in Austin. Its construction is scheduled to begin in the summer. Credit: Battalion Chief Randell Nations, Austin Fire Department via Storyful