PITTSBURGH — A U.S. House committee chairman has begun an investigation into the electrocutions of at least 12 service members in Iraq, including that of a Pittsburgh soldier killed in January by a jolt of electricity while showering.

Rep. Henry Waxman, chairman of the House Committee on Oversight and Government Reform, said Wednesday he has asked Defense Secretary Gates to hand over documents relating to the management of electrical systems at facilities in Iraq.

Staff Sergeant Ryan Maseth, 24, died January 2 of cardiac arrest after being electrocuted while showering at his barracks in Baghdad.

Also Wednesday, Maseth’s parents filed a wrongful death lawsuit in Allegheny County Court against KBR Inc., the Houston-based contractor responsible for maintaining Maseth’s barracks.

The lawsuit, which seeks unspecified damages and costs, alleges that KBR allowed American troops to continue using electrical systems, “which KBR knew to be dangerous and knew had caused prior instances of electrocution.” “I expected that if I lost one of my sons (in the war), it would be due to an IED or firefight,” Maseth’s mother, Cheryl Harris, told the Associated Press on Wednesday. “I never expected to hear he would be electrocuted, that something so senseless happened to him.”

An Army investigation found that his death was due to improper grounding of the electric pump that supplied water to the building, Mr. Waxman said. Maseth died after an electrical short in the pump sent a current through the pipes, the California Democrat wrote in his letter.

A Defense Department spokesman, Chris Isleib, said the Pentagon has turned the matter over to the department’s inspector general for a full investigation.

Since 2003, at least 12 service members have died in Iraq as a result of electrocution, according to the Army and Marine Corps.

In October 2004, Mr. Waxman said in his letter, the Army issued a safety alert that noted five soldiers had been electrocuted that year and improper grounding was a factor in nearly all of the cases. The letter did not give the names of victims other than Maseth. Mr. Waxman asked that his committee be provided investigative reports on the dead soldiers and reports and communications regarding electrical grounding in military facilities in Iraq.

In a January 21 memo responding to questions from Maseth’s family, the Army’s criminal investigations division said the Chinese-made pump was acquired before KBR took over maintenance of the building and did not meet American safety standards. KBR declined to comment on the lawsuit Wednesday, but said it would cooperate with agencies investigating Maseth’s death. The company was formerly owned by Halliburton Co., the oil services conglomerate once led by Vice President Cheney.

Mr. Harris said the military initially did not tell her that her son was electrocuted, and then told her he died “with a small electrical appliance in the shower.” Only later did she learn the truth, she said.

The investigation was sought by Rep. Jason Altmire, a Democrat who represents a district north of Pittsburgh.