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