SALISBURY TWP., Pa. -

Two tractor trailers were involved in a nasty wreck on Interstate 78 East in Lehigh County on Wednesday morning after one truck slammed into the back of another truck.

It happened around 11 a.m. near the Summit Lawn interchange in Salisbury Township.

A driver in a third truck witnessed the crash and quickly sprang into action to help.

"The one truck seemed to be crawling. As he came to a stop, in my peripheral vision, I saw [the other truck] just slammed right into him," said Troy Richards, who witnessed the accident.

According to Richards, the trailing truck started to smoke. A passenger was able to free himself from the wreckage.

"He came out like a bullet, right out of the truck, right over his uncle and down to the ground," Richards said.

But the driver was pinned by the steering wheel.

"The steering column had him pinned in and he couldn't get out, so I pulled as hard as I could and told him to give it all he could to pull his leg out of there," Richards said.

Richards said he was able to pull the driver out of the truck before it became fully engulfed with flames.

"He kept telling me he was going to die. I said 'You're not going to die, you're not going to die.'  I finally got him out.  He was a lucky man today," Richards said.

Three people were injured in the crash, according to officials. Richards said the man who freed himself from the smoldering semi was one of those who suffered injuries in the crash.

"He was hurt pretty good. He was covered in glass and bleeding pretty good," Richards said.

Officials could not provide details on the extent of injuries or the cause of the crash.

A portion of the interstate was closed for approximately two hours while crews cleaned up the scene.