WASHINGTON ( CNN ) -- Private military contractor Blackwater USA `` delayed and impeded '' a congressional probe into the 2004 killings of four of its employees in Falluja , Iraq , the House Oversight Committee said Thursday in a report . Family members of the slain Blackwater employees listen during a congressional hearing earlier this year . Blackwater contractors Jerry Zovko , Scott Helvenston , Mike Teague and Wesley Batalona were ambushed , dragged from their vehicles and killed on March 31 , 2004 . The burned and mutilated remains of two of the men were hung from a bridge over the Euphrates River , an image that fueled American outrage and triggered the first of two attempts to retake the city from Sunni Arab insurgents . The company stalled the committee 's investigation into the incident by `` erroneously claiming '' documents related to the incident were classified , trying to get the Defense Department to make previously unclassified documents classified and `` asserting questionable legal privileges , '' according to a report from the House Oversight and Government Reform Committee 's Democratic staff . According to Blackwater 's reports on the killings , the men killed in Falluja had been sent into the area without proper crew , equipment or even maps . One company document found a `` complete lack of support '' for its Baghdad , Iraq , office from executives at the company 's headquarters in North Carolina , the committee report states . `` According to these documents , Blackwater took on the Falluja mission before its contract officially began , and after being warned by its predecessor that it was too dangerous . It sent its team on the mission without properly armored vehicles and machine guns . And it cut the standard mission team by two members , thus depriving them of rear gunners , '' the report states . In a written response to the report , Blackwater called it `` a one-sided version of this tragic incident . '' `` What the report fails to acknowledge is that the terrorists determined what happened that fateful day in 2004 , '' the company said . `` The terrorists were intent on killing Americans and desecrating their bodies . Documents that the committee has in its possession point out that the Blackwater team was betrayed and directed into a well-planned ambush . '' The report notes that members of the now-defunct Iraqi Civil Defense Corps `` led the team into the ambush , facilitated blocking positions to prevent the team 's escape , and then disappeared . '' Blackwater did not discuss details of the report 's findings , noting the incident is still the subject of a lawsuit by the slain contractors ' families . The committee 's chairman , California Democrat Henry Waxman , has scheduled a hearing Tuesday on Blackwater 's operations in Iraq . The company 's chairman , Erik Prince , is scheduled to testify at that hearing . The committee previously disclosed that the day before the fatal mission , the manager of Blackwater 's Baghdad office warned his bosses he lacked armored vehicles , radio gear and ammunition . During February 's hearing and in a subsequent written response , Blackwater general counsel Andrew Howell told the committee that documents on the attack had been classified by the U.S. government . But the Pentagon later told the committee the documents had not been classified . In addition , Blackwater made `` multiple attempts '' to get the Defense Department to declare company and Coalition Provisional Authority reports on the incident classified , the report states . The Pentagon refused . The families of the slain men have sued Blackwater Security Consulting , one of the most familiar of hundreds of private military contractors operating in Iraq . The families allege the company failed to provide their relatives with adequate gear and weaponry . Blackwater has denied the allegations and argued the men agreed to assume the risks of working in a war zone . Thursday 's report adds to the intense scrutiny the company has faced since it was involved in shootings September 16 in western Baghdad . Iraqi authorities said Blackwater guards protecting a U.S. Embassy convoy opened fire indiscriminately , killing as many as 20 civilians . Blackwater said its employees responded properly to an insurgent attack on the convoy . Deputy Secretary of State John Negroponte on Thursday told a Senate committee that `` something went tragically wrong '' in the Baghdad incident , and that the State Department and Iraqi authorities are conducting a thorough investigation . He said Blackwater guards had fired their weapons on 56 of the 1,873 escort missions they have conducted in Iraq in 2007 , `` And each such incident is reviewed by management officials to ensure that procedures were followed . '' `` I personally was grateful for the presence of my Blackwater security detail , largely comprised of ex-Special Forces and other military , when I served as ambassador to Iraq , '' Negroponte told the Senate Appropriations Committee on Wednesday in response to questions . `` Their alert and controlled posture kept me safe -- to get my job done . '' E-mail to a friend .
the House Oversight Committee probe : Falluja tried to delay , impede investigation into earlier this year killings . one Blackwater employees ambushed , killed in Falluja in 2004 incident . Company said unclassified documents were classified , report says . Blackwater calls report `` a Four -sided version of this tragic incident ''