Two Mehlville Fire Protection District firefighters were injured last week after the roof of an Affton home caved in on them as they battled a fire fed by natural gas and windy conditions.

Affton and Mehlville firefighters responded to a call just before 3 p.m. May 3 in the 9800 block of Tesson Creek Estates Drive in Affton, Mehlville Fire Protection District Chief Tim White said.

They arrived to find the rear of the house in flames and the possibility of residents trapped inside but soon determined the occupants had escaped and began fighting the blaze, White said.

“What they didn’t know was that this was a natural gas fed fire,” White said. “And it made it take off a lot faster … It was at one end of the house and 30 seconds later it was at the other end of the house.”

The roof collapsed while firefighters were inside the house, White said. One Mehlville firefighter suffered second-degree burns when hot embers fell on his neck, which was exposed as falling roof material pushed his head forward. He was treated at a local hospital, released and is back to work, White said.

Another Mehlville firefighter suffered a back injury from the weight of the collapsing roof material. He also was treated at a hospital and released but has not yet returned to work, White said.

Two other firefighters became dehydrated and were given fluids intravenously at the scene, White said.

Officials believe the fire was caused by a discarded cigarette in the back of the house and spread because of a ruptured or exposed gas line and windy conditions that day, White said.

The house likely is a total loss, he said.