LOUISVILLE, Ky. — Police erected concrete barriers and fencing. The mayor declared a state of emergency. More businesses nailed plywood to their storefront windows. Downtown Louisville’s preparations and closures seemed more reminiscent of an approaching hurricane than a grand jury decision. But on Tuesday, Louisville was bracing for an anxiously awaited decision on whether any police officers will be charged in the March 13 shooting death of Breonna Taylor, the 26-year-old unarmed Black woman fatally shot by police who has become a national symbol of racial injustice. Commuters awoke Tuesday morning to eerily empty downtown streets after police erected barricades after midnight in a 25-block perimeter to limit car traffic, including around a park that's been home to nearly four months of protests over the fatal shooting. Kentucky Attorney General Daniel Cameron was expected to announce a decision at any time. By Tuesday evening, it wasn’t clear when that would occur — or what kind of reaction it would spark. Protests in the city, since they began the last weekend in May, have remained largely peaceful, occasionally marred by violence, tear gas and pepper balls. Live updates: Mayor declares 'state of emergency' as downtown access is cut offLouisville Metro Police interim Chief Robert Schroeder said the restrictions, long planned amid “unprecedented times,” were meant to protect public safety, property, protesters and avoid conflicts between drivers and demonstrators. Protesters will still be able to access downtown on foot to demonstrate, he said.“In the community, we’ve all heard the rumors. We all know something is coming. We don’t know what it is,” said Schroeder, whose spokesman said Tuesday there had been no viable threats of violence.“I hope all of this is not needed.”Mayor Greg Fischer issued two executive orders Tuesday. One declared a state of emergency due to the potential for civil unrest, which allows him to exercise such emergency powers as enacting a curfew, and a second one restricts access to five downtown parking garages and on-street parking. If large protests do erupt, police won’t use tear gas unless approved by the chief or deputy chief, or if gunfire erupts, police said — among several policy reforms enacted since the March 13 shooting of Taylor. Federal security personnel have also reportedly been dispatched to protect Broadway’s federal courthouse, which closed for the week. Kentucky Gov. Andy Beshear said the National Guard and Kentucky State Police could serve limited roles in a response.''Our goal with these steps is ensuring space and opportunity for potential protesters to gather and express their First Amendment rights, & to prepare for any eventuality to keep everyone safe,'' Fischer wrote on Twitter. He later called it a ''difficult, tense time for all of us.''Breonna Taylor case: When will Daniel Cameron announce his decision? All Jefferson County circuit, family and district courts would close from 11:30 p.m.