A 31-year-old Whitman native suffered life-threatening burns after pouring gasoline on a backyard fire pit in Abington Saturday night, causing an explosion.

The victim was identified as William Brooks of Lewiston, Maine, by the homeowner, longtime friend Mathew Stephenson.

Brooks’ condition was not available Saturday evening.

After the explosion, the victim was seen “totally engulfed in fire and running across the yard,” said Abington Fire Chief Arthur Pelland.

The victim suffered second- and third-degree burns over an estimated 75 to 80 percent of his body, said Pelland, who described the injuries as life-threatening.

The fire was reported at 7:40 p.m. at Stephenson’s home at 65 Bay State Circle.

Stephenson said he was inside his home putting his 3-year-old son to bed when the explosion occurred.

About 40 people, including a number of children, had been at the home during the day for a birthday party for Stephenson’s son.

Brooks and two other adults were the only people in the backyard at the time of the fire, Stephenson said.

After the fire, tables, chairs and a plastic children’s slide remained in the back yard next to the blackened firepit.

Stephenson estimated that about a half-gallon of gas had been in the can that Brooks used to pour on the fire.

Brooks was on fire for at least 30 seconds after the explosion, Stephenson said.

Abington medical crews requested a MedFlight helicopter to transport the victim to a Boston hospital for treatment, but the helicopter was not available due to stormy weather conditions, Pelland said.

Brooks was taken by ambulance to South Shore Hospital in Weymouth, but hospital staffers were unable to provide his condition as of 10 p.m. Saturday.

Brooks lived in Whitman until about five years ago, Stephenson said.

Two other people in their 30s were in the backyard at the time and suffered burns on their legs, Pelland said. Stephenson identified the two people as Marcy and Kevin Breivogel of Rockland.

They were listed in stable condition at Signature Healthcare Brockton Hospital Saturday night, a hospital spokeswoman said.