Blackwater USA triggered a major battle in Iraq by sending an unprepared team of security guards into an insurgent stronghold in 2004, a move that led to their gruesome deaths and a violent response by U.S. forces, according to a congressional investigation whose findings were released Thursday.The private security company, one o the largest working in Iraq and under intense scrutiny for how it operates, also was faulted for initially insisting its guards were properly prepared and equipped and for impeding the inquiry by the Democratic staff o the House of Representatives Oversight and Government Reform Committee.The results of the staff inquiry come less than a week before Blackwater founder Erik Prince is scheduled to testify before the Oversight Committee, which is chaired by Representative Henry Waxman (Democrat from California), a longtime critic of Blackwater.The March 2004 incident involving Blackwater was widely viewed as a turning point in the Iraq war after images of the mutilated bodies of the four guards were seen around the world. Four days after the Blackwater guards were killed, a major military offensive began in Fallujah.The combat lasted nearly a month. At least 36 U.S. military personnel were killed, along with 200 insurgents and an estimated 600 civilians, according to the congressional investigation.In a statement, Blackwater spokeswoman Anne Tyrrell called the congressional repot a “one-sided version” of a tragic incident. She said the committee has documents that show the Blackwater team was ‘betrayed” and steered into “a well-planned ambush.Tyrrell said the report does not acknowledge “that the terrorists determined what happened that fateful day in 2004,” and that “the terrorists were intent on killing Americans and desecrating their bodies.