WASHINGTON — An Army investigation calls the electrocution death of a U.S. soldier in Iraq "negligent homicide" caused by military contractor KBR Inc. and two of its supervisors.

In a document obtained by The Associated Press, an Army criminal investigator says the manner of death for Staff Sgt. Ryan Maseth, 24, of Allison Park, Allegheny County, has been changed from accidental to negligent homicide because the contractor failed to ensure that "qualified electricians and plumbers" worked on the barracks showers in Baghdad, where Maseth died Jan 2, 2008.

Maseth, a Green Beret, was the son of Cheryl A. Harris of Cranberry Township.