Fire Sweeps Construction Site of Luxury Apartments : Accident: Blaze destroys 238 units. Firefighters were hampered by dry winds and lack of access to water.

Fire surged through at least 21 buildings of finished and half-built luxury apartments in Thousand Oaks Saturday afternoon, straining water supplies before firefighters brought the flames under control.

Despite the dust-dry 25-m.p.h. winds and hydrants sealed off from firefighters by a ring of flames, the blaze at The Knolls was under control just two hours after firefighters arrived shortly before 3 p.m. About 30 engine and hand crews from Ventura and Los Angeles counties fire departments turned out to fight the blaze.

Two helicopters ferried in water to supplement a meager supply flowing from the only two accessible fire hydrants. Fire, accelerated by bursts of hot, dry wind, swept through the open-beam unfinished construction, at one point forcing engines back from the searing intensity.

Two firefighters suffered minor injuries, and one of them was hospitalized for smoke inhalation, fire officials said.

The blaze destroyed 238 apartments as it hurtled through a portion of the lavish 540-unit complex--designed with tennis courts, spas and pools and scheduled for its first occupants at the end of the month--after a workman accidentally set some piping wire afire, said Ventura County fire spokesman John Wade.

A plumbing contractor doing silver soldering on the first floor of one apartment inadvertently set the wire smoldering and, unknown to him, the spark spread through the wire to the second floor, where the blaze began in earnest.

“He was on the first floor,” Wade said. “He did not even realize that the fire had made a run to the second floor.” The workman alerted a security guard, who telephoned the Fire Department.

Ironically, the roofing tiles that sometimes ward off leaping flames had not yet been installed on some roofs of the building project, and stacks of them sat waiting on the burning roof of one townhouse.

A damage estimate was not available.

A few residents living in established neighborhoods within a few hundred yards of the complex said sheriff’s deputies at one point told them to evacuate, but the fire was in hand before many people began to do so. Officials briefly thought they might have to evacuate a home for cerebral palsy patients, about two miles north of the fire and behind some hills, but did not.

Along the rims of nearby hillsides, dozens of residents of adjacent neighborhoods stood watching the spectacle of embers and smoke, to the annoyance of firefighters. Sheriff’s deputies yelled a warning at gawkers parked and standing in a nearby intersection.

Sparks from the enormous blaze leaped ahead into a patch of brush about a mile away, and other firefighters worked to keep that separate fire in hand, Denise Oblinger, a Ventura County Fire Department spokeswoman.

At The Knolls’ office near some finished apartments, workers evacuated themselves and their equipment, “as much as we can,” said one woman carrying a computer printer to her car.

Times staff writer Psyche Pascual contributed to this report.