DETROIT -- An underground electrical explosion Saturday morning in downtown Detroit caused damage and disruptions but no injuries, authorities said.
The city's Homeland Security and Emergency Management reported the explosion happened at an underground electrical substation in the central business district. Police say the blast caused manhole covers to shoot into the air. Streets were blocked and buildings were locked down in the immediate area.
The Detroit Fire Department and utility DTE Energy are investigating.
Detroit Police said two officers on patrol heard the loud blast and found a manhole cover that was ajar. Several residents of Washington Boulevard Apartments say they heard the blast or saw its effects.
"All up and down the alley, the covers started blowing up and the lights were flickering and the elevator stopped working," Diane Hudson, who watched from her sixth-floor window, told The Detroit News.
Detroit resident David Crumbie said he was sitting in a park next to his bike with a friend at the time of the blast, which knocked the chain off his bike.
"Blond smoke just came out of the ground below us," he told the newspaper. "It was a big boom like a bomb."