On the night a fatal fire swept through a West Chester nursing home, water to the sprinkler system was turned off, lawyers for the families of three of the victims say they have been told by an engineer hired by the home.

In addition, the warning system for the sprinklers was giving a false reading that the water was on, according to lawyers with the McEldrew Young and Robert Mongeluzzi law firms.

The lawyers said the revelations came during a December briefing by Dan Arnold, an engineer with Seneca Fire Engineering, an Atlanta firm working for Barclay Friends, a wing of which was gutted by the fast-moving fire Nov. 16.

At the briefing, Arnold informed other engineers and attorneys that investigators for the Bureau of Alcohol, Tobacco, Firearms and Explosives told him that they had determined that the large wheel used to control water to the sprinkler system was in an off position after the fire, according to Ian Bryson, a lawyer with McEldrew Young, and Samuel Dordick, a lawyer with the Mongeluzzi firm. Both attended the briefing.

Arnold declined to comment Monday. "I am not authorized to talk about it at all," he said. He referred a reporter to Paul Bartolacci, an attorney for Barclay Friends. He did not return messages seeking comment. A spokeswoman with the ATF also declined to comment.

The valve for the sprinkler water was housed inside a locked mechanical room, according to Bryson and Dordick. The lawyers said Arnold reported that ATF investigators said they were the first to unlock the door after the fire and found the wheel turned to its off position.

The fact that the mechanical room, walled with cinder blocks and in a section untouched by fire, was unlocked only after the blaze appears to rule out the possibility that the water was turned off by firefighters seeking to get more pressure for their hoses or later to stop the sprinklers from dousing the rubble.

The fire began about 10:45 p.m. on a cold and gusty night in the rear of the personal-care section of the seven-wing complex. The five-alarm fire gutted the section, home to 41 elderly residents. The six other wings, far less damaged, were home to some 100 residents receiving nursing care.

Killed from smoke inhalation were four tenants in the personal-care section: Theresa Malloy, 85; Mildred E. Gadde, 93; and  Delores G. Parker, 89, and her husband, Thomas F. Parker, 92.

The Inquirer and Daily News reported last month that the sprinkler system had multiple design flaws that could have reduced its effectiveness in slowing the blaze. Donald Vess, the designer of the system, has acknowledged mistakes in his plans but said the errors were "typos" of little consequence. Other experts said they raised concerns.

Bryson said his firm hired experts on construction, fire causation, and fire response to answer why so many died in a section of the facility protected by more than 500 sprinklers. His firm represents the family of the Parkers, who had three children and six grandchildren.

"The loss their family suffered as a result of this catastrophe cannot be put into words," Bryson said. "Unfortunately, it could have been easily avoided but for the failure of the facility to conform to basic life and fire safety requirements."

Andrew Duffy, with the Mongeluzzi firm, which filed a lawsuit late last month on behalf of the Malloy family, said none of the fleeing residents of the home saw any evidence that the sprinklers were working.

"Right now, it is our belief that there was no water coming out of the system,"  Duffy added. "That means either the valve was closed or there was some other rupture to the system."

But if the valve was closed, why didn't Barclay Farms realize that water was cut off?

In late December, Seneca inspected the warning system, known as a "tamper switch," which sits below the valve. The inspection was videoed and watched live by a battery of  lawyers and experts representing insurers and others. The video, reviewed by the Inquirer and Daily News, shows that the switch provided erratic readings, signaling that the valve was open even when it was closed. "Fully closed — and never activated," Arnold noted at one point in the video, referring to the alarm.

In recent interviews, John H. Morley Jr., a fire-protection contractor in Philadelphia, said that he sometimes finds the water valve shut on a sprinkler network he has inspected. Of perhaps 30 inspections in the last 18 months, he said, water was turned off in three systems. According to Morley, a key test during inspections calls for turning off the valve briefly, and workers simply forget to turn the valve back on.

Morley had another observation. In inspections, he said, it is even more common to find the warning systems inoperable.

In an interview, Larry Elveru, spokesman for Kendal Corp., parent company for Barclay Friends and a dozen other Quaker-oriented homes in eight states, initially said the sprinkler system at Barclay was last tested in August, part of a protocol of quarterly checks. After saying he wanted to double-check those facts, Elveru declined further comment, citing the ongoing investigations. He could not be reached Monday.

The tests were done by Simplex Grinnel, a part of Johnson Controls, a Wisconsin-based firm. Its spokesman, Fraser Engerman, declined comment via an email.

"This is an ongoing investigation and Johnson Controls is cooperating with authorities," Engerman said. "We continue to extend our thoughts and prayers to the families and individuals affected."