Interstate 95: Section of NB I - Kunming Semi Trailers Inc.

PHILADELPHIA -- A section of northbound I-95 in Philadelphia has collapsed after a tanker truck caught fire underneath the highway, Philadelphia officials said Sunday morning.

"We did have a collapse of 95 on the northbound side, and the southbound side is compromised by heavy fire," Derek Bowmer, battalion chief for the Philadelphia Fire Department, said during a news conference Sunday morning. "It looked like we had a lot of heat and heavy fire underneath the underpass."

Firefighters are still battling the blaze, Bowmer said.

Explosions around the highway collapse were caused by "runoff of maybe some fuel or gas lines that could have been compromised by the accident," said Bowmer.

"We have fire coming out of those manholes," Bowmer said.

Photos and videos from the scene show huge plumes of smoke billowing from the interstate.

The mayor's office told CNN a large tanker truck fire caused the collapse. The highway is closed in both directions around the area and the fire is under control, according to Sarah Peterson, the office's communications director.

Dominick Mireles, director of Philadelphia's Office of Emergency Management, said officials would be dealing with the collapse and the fire for a long time.

"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," Mireles said. "The roadway's gone."

Tumar Alexander, managing director for the City of Philadelphia, said the incident will "be a significant impact to this community for a while."

"95 will be impacted for a long time," Alexander said during the news conference.

The fire is under investigation by the fire marshal and other partners, Bowmer added during the news conference.

The Philadelphia Office of Emergency Management urged travelers to avoid the area and seek alternate routes in a Sunday morning tweet.

Pennsylvania Governor Josh Shapiro has been briefed on the collapse, according to a Twitter thread Sunday.

"I was just briefed by @PEMAHQ, @PennDOTNews, and @PAStatePolice on the I-95 fire and collapse in Philadelphia. State Police and PEMA are on the scene assisting local first responders and @PennDOTSec and his team are en route to assess the situation and address traffic needs," said the governor on his verified Twitter account.

"@LTGDavis and I are closely coordinating with partners in Philadelphia, New Jersey, and the federal government and we will share more information as we have it. For now, please avoid the area and follow the direction of the first responders on the scene."

Officials have not reported on any injuries.