$3.5-Million Fire Hits Apartments : Westside: A structure under construction is destroyed when a plumber’s torch ignites the flames and 19 neighboring units are damaged. A worker and three firefighters are injured.

Flames that spewed suddenly from a plumber’s torch ignited a 40-unit wood-frame apartment house under construction in Brentwood and burned it to its foundation Thursday, injuring a worker and three firefighters and damaging 19 neighboring apartments.

The fire, which broke out just after 8 a.m., forced the evacuation of more than 100 people, left dozens homeless, knocked out power for four city blocks and left area traffic snarled for hours in the residential West Los Angeles neighborhood.

More than 200 Los Angeles firefighters worked for two hours to quench the flames, which swiftly devoured the three-story structure on Montana Avenue and reached temperatures of 2,000 degrees Fahrenheit, melting car taillights and a metal sign more than 20 feet away.

Radiant heat set drapes ablaze in a building to the east, eventually burning out 11 apartments, Los Angeles Fire Department officials said. The heat also blistered paint and shattered picture windows on a building to the west, where eight units suffered water and smoke damage after the wood-shake roof-line trim caught fire, they said.

“There’s nothing to stop it,” said Los Angeles Fire Department Deputy Chief Don Anthony as his crews hacked at the western building’s burning parapet with axes. “You could not build a better bonfire if you tried.”

Firefighters were able to control the fire by 9:48 a.m. A Department of Water and Power spokesman said power was restored to most customers by 11:20 a.m.

Los Angeles Fire Department spokesman Jim Wells said that investigators had not determined what caused the plumber’s torch to ignite the fire. He put preliminary damage estimates at more than $3.5 million.

Three firefighters suffered minor injuries, said UCLA Medical Center spokesman Mike Byrne. All were treated and released, he said.

Construction workers said the fire began in the middle of the second floor, where plumbers were using acetylene torches to solder sections of water pipe together. The 2-foot-high, 10-inch-diameter acetylene tank that they were tapped into suddenly erupted in flames, said plumber Carl Hughes, 39. “We don’t know what happened. It just popped and ignited. Once the hose burned off, it was just out of control.”

Plumbing foreman Fernando Macias suffered burn blisters on his left arm when he tried to throw the burning tank out of the building, his fellow workers said. He was later treated for burns at UCLA Medical Center, officials said.

Despite the plumbers’ efforts to douse the fire with extinguishers, it burned out of control, forcing them to flee, Hughes said.

“Everybody was scampering,” said Robert McBride, 27, a plumber who had been working downstairs. “I just made it out. It was just scary.”

As the workers fled the blazing structure, two scaled the balconies of the adjacent building to the east at 11666 Montana, went inside and began pounding on apartment doors.

When fire alarms began ringing, “I looked out in the hall, didn’t see anything and went back to bed,” said Howard Graham, 77, who with his wife, Sylvia, 68, surveyed the tangle of fire hoses leading to the building, where they have lived for 17 years.

“A little bit later, somebody banged on the door, and I looked out again . . . and there was heavy smoke, the black stuff, you couldn’t walk through it.”

Framer Bill Krisatis stayed with the couple until a firefighter led them through the smoke to safety, the Grahams said.

“We were probably the last four to get out,” said Krisatis, 27.

At 11690 Montana, the apartment building to the west, Carole Franklin said she was “kind of lounging in bed when all of a sudden my intercom went off, and there was somebody yelling, ‘Get out, there’s a building on fire!’ ”

Franklin threw on a bathrobe and a pair of slippers, grabbed her purse and fled.

Two hours later, she was still on the street, making plans to stay with her son in West Los Angeles.

“If I thought I was going to be out this long, I would have gotten dressed,” Franklin said with a sigh. She was recently laid off from her job. “November has not been great.”

Nearby, an elderly woman rested on a low wall, sniffing uncomfortably at the smoke coming from her burning apartment building.

“I never dreamed a thing like this would happen,” said the woman, who asked not to be identified. “You hear about it, you see it on TV, but you never think it could happen to you.”