40 Condos Gutted in Suspicious $6-Million Blaze : Fire: Forty other units are heavily damaged. Officials are investigating the possibility of arson.

A fire destroyed 40 condominium units under construction in Lancaster on Saturday and heavily damaged at least 40 other units in a $6-million blaze that Los Angeles County fire officials described as suspicious in origin.

The blaze erupted at 2:45 p.m. in a 130-unit development in the rapidly growing Antelope Valley city. Smoke billowing two miles high drew hundreds of spectators, temporarily blocking firefighters’ access to the site at 30th Street West and Avenue K-4, Fire Department spokesman Robert Serabia said.

About 250 firefighters, assisted by two water-dropping helicopters, battled the fire for 90 minutes before bringing it under control, Serabia said. Five firefighters were treated for heat exhaustion. No other injuries were reported.

“You could see the fire from all over the valley, and people were driving that far,” Serabia said. “I was in a traffic jam trying to get to the fire.”

The fire, in the Marbella Villas development, engulfed 20 two-story buildings with four units each, Serabia said. Embers ignited a quarter-acre of grass across the street and sparked small fires on a roof and in an attic about one mile away, officials said. Those fires were quickly extinguished.

Fire Department spokesman Don Kanallakan said firefighters’ efforts were hampered by wind gusts of up to 35 m.p.h. and 85-degree heat.

Kanallakan added that investigators were having difficulty pinpointing the fire’s origin because of the project’s size.

Fire officials were investigating the possibility of arson because the first flames spread rapidly through dozens of units and because there were no construction workers present who might have set the fire inadvertently. The cause of the fire had not been determined Saturday night.

The destroyed condominiums were about 50% complete, Serabia said. Firefighters were able to save about 50 nearly completed units, valued at about $3 million, Kanallakan said. The scheduled opening of those units next month may be delayed until the Fire Department completes a structural inspection, Serabia said.

The blaze was similar to three fires that caused damage of more than $3 million to 45 houses under construction in Palmdale and Quartz Hill last August and September. Officials said that those fires appeared to have been accidental, in one instance caused by a plumber’s torch.

The condominium project is being developed by Hamdan Associates, based in Century City, Serabia said. Developer Khalil Hamdan, who was at the project inspecting the damage Saturday afternoon, declined to comment.