A section of Interstate 95 in Philadelphia collapsed Sunday morning following a large tanker truck fire under the highway, city officials said.
The sudden cave-in of the busy stretch of roadway created an immediate traffic nightmare for the roughly 160,000 vehicles that pass through each day.
"Remarkable devastation," Pennsylvania Gov. Josh Shapiro said at a news conference Sunday evening after surveying the damage.
"I found myself thanking the lord that no motorists who were on I-95 were injured or died. It's just a remarkably devastating sight," he added.
A photo shared by the city's Office of Emergency Management showed a scorched section of the highway caved in on the road below. Images on local news and social media showed black smoke billowing from the area.
No injuries had been reported and it was unclear what caused the vehicle fire. The National Transportation Safety Board said it was investigating the incident in coordination with the Pennsylvania State Police.
The roadway will take months to repair, Shapiro said. All of the elevated northbound lanes collapsed, while the southbound lanes were heavily damaged. A similar highway collapse in Atlanta in 2017 took about six weeks to repair.
U.S. Secretary of Transportation Pete Buttigieg said the federal government would provide any resources it can to help with the recovery effort and the rebuilding process.
"This is a major artery for people and goods, and the closure will have significant impacts on the city and region until reconstruction and recovery are complete," he said.
Officials said there had been no impacts on the city's drinking water supply.
Traffic was stopped in both directions near the site of the collapse, and officials were urging drivers to take alternate routes.
SEPTA, the area's public transit agency, was adding more cars per train to its regional rail lines serving the area, according to general manager Leslie Richards.
"We are all going to need some extra patience in the coming days. Please work with us as we work through this," she said.
Earlier in the day, Philadelphia Fire Department battalion chief Derek Bowmer said explosions heard in the area after the accident were "runoff" from fuel or gas lines that may have been compromised by the fire.
"We have fire coming out of those manholes," he said.
The fire department responded to the call around 6:30 a.m. local time Sunday morning and had the fire contained by 7:30 a.m.
The collapse occurred near the Cottman Avenue exit of I-95 in Northeast Philadelphia.