Gloucester, MA – Ken Maciel said that, as soon as he heard an explosion, he looked out the window of his own home at 75 Woodman St. and could see that his mother’s house was on fire.

His mother, Jean, who owns the house at 79 Woodman, was visiting him and his family at the time, so he knew she was safe. But he raced several yards next door to see if there was anything he could do.

“I got there in about 30 seconds,” he said Sunday, a day after fire raced through his mother’s single-story, wood frame home.“For a few seconds, I contemplated trying to go in and getting stuff out, but the house was built 51 years ago, I knew the wood that was used, and I just decided I’d better not. I could see what was happening.”

Gloucester Fire Chief Eric Smith said Sunday that a propane leak in lines that fed a basement hot water heater, sparked by the adjacent oil furnace, likely sparked the explosion. No one was in the house at the time.

The blast then triggered a fire that sped up through the house and up into the attic, leaving little more than the exterior shell of the pink home that sits near the end of the narrow West Gloucester street.

The double-alarm fire drew more than 20 Gloucester firefighters, bolstered by four-man crews and engines from Essex and Beverly, as well as Manchester firefighters.Off-duty Gloucester firefighters and Beverly and Hamilton firefighters covered the Gloucester station.

Deputy Chief Steve Aiello said at the scene Saturday that when the first crew arrived after receiving several calls about the explosion around 4:30 p.m., the basement windows were blown out, and heavy fire was climbing from the cellar to the first floor.

Smith and Deputy Fire Chief Andrew McRobb, who was among those on the scene, said that the Essex water tanker was used as a water shuttle to the scene, drawing from the nearest hydrant. But that hydrant was nearly a half-mile away at the bottom of the hill and the narrow roadway, which winds up into the woods off Essex Avenue roughly a quarter mile from the Essex town line.

“(Firefighters) were able to get the bulk of the fire in the basement knocked down quickly,” Smith said, “but you need sustained pressure to keep on it, and with the limited water source, (the fire) extended quickly up through the floor into the attic space. Then we were chasing it, and unfortunately, with the limited water supply and a compromised building, we couldn’t really send people inside to fight it. We didn’t want to put anyone in jeopardy.”