Fire Loss Is Revised Upward to $12 Million : Thousand Oaks: The destruction of 330 apartments was hastened by low water pressure. There is no evidence that hydrants had been turned off.

Fire officials investigating a blaze that destroyed 21 apartment buildings under construction in Thousand Oaks raised the damage estimate to $12 million on Sunday and said low water pressure hindered firefighters.

But the investigators said they do not know that any hydrants were turned off, as officials had said during the blaze Saturday.

Instead, they now believe that some hydrants were rendered useless as pipes burst in the burning buildings and as several fire hoses were hooked into the system at the same time, causing water pressure to drop dramatically.

“The rumors were flying last night that the hydrants weren’t on, but it looks like that may not have been true,” said Ventura County fire investigator Bill Hager. “We jumped to some sensational conclusions without the facts.”

All of the buildings under construction at The Knolls complex on Avenida de los Arboles had water connections, Hager said. As the buildings collapsed, broken pipes sent about 1,000 gallons of water per minute flowing down the streets, carrying softball-size boulders into storm drains.

Officials said the investigation is continuing, but they said that before construction began the developer apparently had complied with the department’s requirement that all hydrants be operating.

Don Nelson, the city’s director of utilities, said the water system provided twice as much water as is required by fire codes, but added that the hydrant system is designed to fight individual fires, not groups of buildings burning simultaneously.

“It was an inferno,” Nelson said. He said city officials and the county Fire Department will meet to discuss whether changes are warranted.

Firefighters said low water pressure was just one of several problems that allowed the blaze to spread rapidly and destroy 330 of the 544 apartments at the complex, which were to have been rented for $700 to $1,200 a month. High winds, low humidity, the proximity of buildings to one another and the fact that the complex was in “the most volatile stage of construction” also contributed to the severity of the blaze, said John Wade, county Fire Department spokesman.

“It’s just a real dangerous, critical point of a construction job,” he said, noting that many of the buildings were still exposed wood frames that did not have tile roofs that might have hindered the fire’s spread.

Wind gusts clocked at 25 m.p.h. allowed the fire to jump quickly to adjacent buildings, some of which were only 12 feet apart, Wade said.

The blaze was ignited about 3 p.m. by a plumber using a torch to solder a pipe, officials said. It destroyed 21 buildings and damaged another for a loss of about $10 million, Wade said. Another $2 million in construction equipment was destroyed. On Saturday, officials had predicted a damage total of about $7 million.

The fire was contained by 9 p.m., but buildings continued to smolder through the night.

On Sunday, onlookers climbed a nearby hillside to watch 85 firefighters wrap up the operation. Bulldozers ripped down ruined but still erect buildings so firefighters could search for embers that might reignite the rubble. Other firefighters, armed with hoses, sprayed water on the ruins, which eventually will be hauled to a landfill, Wade said.

Officials of Newport Beach-based Regis Homes Corp., the project’s co-owner, declined to comment Sunday. Officials at the Ventura headquarters of Interstate Plumbing Inc., employer of the plumber who accidentally started the fire, and at the Thousand Oaks offices of the Lang Ranch Co., the project’s co-owner and developer, could not be reached.

The western side of the complex, where the buildings were protected by tile roofs, was not damaged. Plants sat in plastic pots on Sunday, waiting to be planted as landscaping.

Eighty of those units have been rented, and tenants had planned to move in as early as Nov. 19.

Wade said at least some of the damage will be covered by insurance.

About 250 firefighters battled the blaze, including ones from Ventura County, Los Angeles County, Los Angeles, Oxnard, the California Department of Forestry and Fire Protection, Camarillo State Hospital and the Pacific Missile Test Center at Point Mugu.

Four firefighters suffered minor injuries.

Ventura County Fire Capt. Larry Henry suffered from heat exhaustion and smoke inhalation and Battalion Chief Bob Stone scratched the cornea of his eye, probably when embers flew into it, Wade said. Both men were treated at Los Robles Regional Medical Center in Thousand Oaks and released, Wade said.

An unidentified Los Angeles firefighter sprained his ankle, and another Los Angeles firefighter, identified only as a Ventura County resident who was off-duty but helped fight the blaze, suffered an unspecified injury that did not require treatment.

Thousand Oaks Mayor Alex Fiore said he did not believe that the fire would affect the project’s building permits or other approvals, and he doubted that the City Council will have an opportunity to reconsider the project.

Four years ago the development sparked a battle between the developer and homeowner groups, which claimed that the development violated Thousand Oaks’ strict growth-control ordinance.

Faced with a multimillion-dollar lawsuit filed by the developer, the City Council in September, 1988, unanimously approved the project, which ultimately calls for 2,257 units on the 2,500-acre Lang Ranch.

Homeowners sued the city a month later, claiming the project made a mockery of a growth-control ordinance passed in 1980. Homeowners feared the development, east of the Moorpark Freeway between Avenida de los Arboles and Sunset Boulevard, would increase traffic and worsen air quality.

But a judge rejected the suit, saying that city officials agreed in 1971 to exempt the land from any future growth-control ordinance.

Times staff writers Aaron Curtiss and Philipp Gollner and correspondent Stephanie Stassel contributed to this article.