Video from the scene showed a massive concrete slab had fallen from I-95 Interstate onto the road below in northeast Philadelphia. There were no immediate reports of injuries.
An elevated section of Interstate 95 collapsed early Sunday in Philadelphia after a vehicle caught fire, closing the main north-south highway on the East Coast and threatening to upend travel in parts of the densely populated Northeast, authorities said.
Transportation officials warned of extensive delays and street closures and urged drivers to avoid the area.
Early reports indicated that the vehicle may have been a tanker truck, but officials could not immediately confirm that.
The fire was reported to be under control.
Video from the scene showed a massive concrete slab had fallen from I-95 onto the road below in northeast Philadelphia. There were no immediate reports of injuries.
The northbound lanes of I-95 were gone, and the southbound lanes were “compromised” due to heat from the fire, said Derek Bowmer, battalion chief of the Philadelphia Fire Department.
Runoff from the fire or perhaps broken gas lines were causing explosions underground, he added.
Mark Fusetti, a retired Philadelphia police sergeant, said he was driving south toward the city's airport when he noticed thick plumes of black smoke rising over the highway. As he passed the fire, the road beneath began to “dip”, creating a noticeable depression that was visible in video he took of the scene, he said.
He saw traffic in his rearview mirror come to a halt. Soon after, the northbound lanes of the highway crumbled.
“It was crazy timing,” Fusetti said. “For it to buckle and collapse that quickly, it's pretty remarkable.”
Officials were also concerned about the environmental effects of runoff into the nearby Delaware River.
“Today's going to be a long day. And obviously, with 95 northbound gone and southbound questionable, it's going to be even longer than that,” said Dominick Mireles, director of Philadelphia's Office of Emergency Management.
Heavy construction equipment would be required to start to remove the debris, he said.
Officials planned to launch a drone to assess the damage.
The fire was strikingly similar to another blaze in Philadelphia in March 1996, when an illegal tire dump under I-95 caught fire, melting guard rails and buckling the pavement.
The highway was closed for several weeks, and partial closures lasted for six months. Seven teenagers were charged with arson.
The dump's owner was sentenced to seven to 14 years in prison and ordered to pay $3 million of the $6.5 million repair costs, The Philadelphia Inquirer reported.
More recently in Atlanta, a massive fire collapsed an elevated portion of Interstate 85, shutting down the heavily travelled route through the heart of the city in March 2017.
A homeless man was accused of starting the blaze, but federal investigators said in a report that the state transportation department's practice of storing combustible construction materials under the highway increased the risk of fire.