Knoxville (WVLT) -- A tractor trailer toppled off of I-40 onto Papermill Drive after 8am this morning.
"I just heard like an explosion and I seen a semi truck rolling right off the freeway," said a taxi driver who saw the accident unfold.
"This is the worst wreck I've ever seen," said Gary McGill, "I thought somebody was killed when I first saw the wreck. It looked so bad."
Motorists traveling east on I-40 were delayed for moments this morning as crews tried to put out flames from the explosion and clean up the interstate for other travelers.
"It's a pretty incredible, they not only came through the guard rail, but they took out a directional sign, the entire pole, then rolled down this embankment," said Darrell Whitaker, Community Relations Officer for the Knoxville Fire Department.
"I've never seen a tractor trailer all twisted up like this," said Fred Allen, another motorist who was able to see what was left of the tractor trailer.
He along with others saw clouds of smoke and lights along Papermill Drive in west Knoxville for hours.
"I'm just wondering how the guy lived after he rolled off that bank, it's a miracle he's alive," said Allen.
"His front axle, it just held the two gentleman long enough before the truck rolled over and exploded and they got out," said the nearby taxi driver.
The truck driver along with two other juvenile passengers were able to escape from the semi before it burst into flames.
"It could have been a lot worse," said Bill Terell, another motorist who witnessed the truck make its tumble from the interstate on the road.
"Obviously, he could've landed on top of a car or something," he said.
"We do see an axle laying off on the side here and it's front end of the truck, so we don't know if he blew a tire or actually lost the frame itself," said Whitaker.
Crews were on the scene all day trying to figure out exactly what happened in the accident.
"This truck was carrying vinyl siding and with vinyl siding highly combustible, it really burned pretty heavy and they had to use foam products to extinguish this fire," he said.
TDOT won't be able to begin the full assessment of the damages until tomorrow but did say the guard rail on I-40 will have to be replaced, along with the overhead sign and pole, and the camera that was mounted on top of the pole.
The driver's insurance company will have to reimburse the state for the damages.
All of the passengers in the truck were able to leave the scene with minor injuries.
TDOT tells us they're still assessing the damage.
They say they will have to replace the torn out guard rail, overhead sign and pole that had their camera mounted on it.
There is no estimated cost yet, but officials says the driver's insurance will have to reimburse the state.
The relationship between the driver and the juveniles is not yet known.