A devastating fire involving a tanker truck and two cars created havoc on the Pennsylvania Turnpike and killed three people late Saturday morning, state police said. 

At least one of the vehicles turned into a rolling inferno on the northbound side of Interstate 476 shortly before 10:30 a.m., shutting down all lanes between Mid-County and Lansdale in Worcester Township, Montgomery County.

Troopers said that a vehicle with a flat tire came to a stop in the right lane of the highway and another vehicle behind it stopped and the driver activated hazard lights. The truck was unable to stop and struck both vehicles, and all three became engulfed in flames, police said.

The person driving the commercial tanker truck – which was carrying jet fuel – and one person driving what investigators call "Unit 2" died on the scene due to fire in the vehicles, according to state police. On Monday, they added that a third person who was also in Unit 2 died.

DEVASTATING TANKER FIRE KILLS AT LEAST 1 PERSON, SHUTS DOWN MAJOR PENNSYLVANIA HIGHWAY: VIDEO

A large black cloud of smoke rises from the scene of the vehicle fire on the Pennsylvania turnpike.

A large black cloud of smoke rises from the scene of the vehicle fire on the Pennsylvania Turnpike. ( @newsguyPhilly/X)

"We do not have confirmed identities of the deceased due to the severity of the crash and the fire involved," a statement to Fox News Digital said.

State police do not have on update on the condition of the driver of a white Acura, referred to as Unit 1. 

Social media images and videos showed a large cloud of black smoke rising from the scene and blanketing the highway with debris.

Emergency personnel were first called to the scene at 10:24 a.m., northpennnow.com reported. 

Videos taken by @newsguyPhilly — published on X and shared with Fox News Digital — show firefighters wrestling with the blaze. 

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Firefighters hitting a burning tanker with water and foam

The Official Pennsylvania Turnpike X account posted at 12:01 p.m. that firefighters are still getting the fire under control with water and foam. ( @newsguyPhilly/X)

Miles of bumper-to-bumper standstill traffic

Traffic was shut down on the Pennsylvania Turnpike for hours. (Ed McFarland)

People were trapped on the road for hours. One driver, Ed McFarland, told Fox News Digital that there were miles of bumper-to-bumper traffic.

"We're going nowhere fast," McFarland said at 12:34 p.m. "I can’t see anything but stopped traffic and people out of their cars. The smoke is gone at this point."

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Southbound lanes were reopened Saturday evening and northbound lanes had reopened by early Sunday.

Fox New's Sarah Rumpf-Whitten and The Associated Press contributed to this report.