POWNAL – A man using a torch to cut into a junked car Monday afternoon was burned over 90 percent of his body when the vehicle gas tank exploded, fire investigators said.

The man, described as in his late 50s, suffered first-, second- and third-degree burns in the 2:30 p.m. blast on Chadsey Road.

The victim, who was not identified Monday night, was taken to Pownal Elementary School where LifeLight helicopter had landed to fly him to a Boston hospital.

Investigators said the blast occurred while the man was working on a disabled car in a field at the back of his home at 198 Chadsey Road.

Richard Shepard, senior investigator with the State Fire Marshall’s Office, said the man was using an oxyacetylene cutting torch when the blast occurred.

“It appears he was cutting the straps the hold the gas tank in place in order to remove it from the vehicle,” Shepard said. “The tank exploded.”

The victim had already removed the catalytic converter from the vehicle, Shepard said. He described the blast as a “boiling liquid expanding vapor explosion.”

The victim lives at the Chadsey Road home with his wife and children, Shepard said. They were able to get the man into the shower while rescue crews responded.

“He was conscious and talking through the whole thing,” Shepard said.

The burned man was taken to Massachusetts General Hospital. Shepard said he is hoping to speak with the victim once he is able.

Officials from the Cumberland County Sheriff’s Department were assisting with the investigation.