Senior managers for defense contractor KBR overruled calls to halt supply operations in Iraq in the spring of 2004, ordering unarmored trucks into an active combat zone where six civilian drivers died in an ambush, according to newly available documents.

Company e-mails and other internal communications reveal that before KBR dispatched the convoy, a chorus of security advisors predicted an increase in roadside bombings and attacks on Iraq's highways. They recommended suspension of convoys.

"[I] think we will get people injured or killed tomorrow," warned KBR regional security chief George Seagle, citing "tons of intel." But in an e-mail sent a day before the convoy was dispatched, he also acknowledged: "Big politics and contract issues involved."

KBR was under intense pressure from the military to deliver on its multibillion-dollar contract to transport food, fuel and other vital supplies to U.S. soldiers. At Baghdad's airport, a shortage of jet fuel threatened to ground some units.

After consulting with military commanders, KBR's top managers decided to keep the convoys rolling. "If the [Army] pushes, then we push, too," wrote an aide to Craig Peterson, KBR's top official in Iraq.

The decision prompted a raging internal debate that is detailed in private KBR documents, some under court seal, that were reviewed by The Times.

One KBR management official threatened to resign when superiors ordered truckers to continue driving. "I cannot consciously sit back and allow unarmed civilians to get picked apart," wrote Keith Richard, chief of the trucking operation.

Six American truck drivers and two U.S. soldiers were killed when the convoy rumbled into a five-mile gauntlet of weapons fire on April 9, 2004, making an emergency delivery of jet fuel to the airport. One soldier and a seventh trucker remain missing.

Recriminations began the same day.

"Can anyone explain to me why we put civilians in the middle of known ambush sites?" demanded one security advisor in an e-mail. "Maybe we should put body bags on the packing list for our drivers."

Another wrote, "I cannot believe this has happened; the ones responsible should be held accountable for this."

The previously undisclosed documents raise new questions about the U.S. military's growing reliance on civilian contractors to help fight wars.

Selected e-mails, some of them excerpts, were cited in a May 22 letter to the Justice Department by lawyers suing the Houston-based giant on behalf of the dead drivers' families. The families and most of the survivors of the convoy seek a federal criminal probe of KBR's role in the episode.

To confirm the excerpts, The Times reviewed internal memos, e-mails and court-sealed depositions, obtained a copy of an Army investigative report on the incident and interviewed several KBR truck drivers and former military officials.

Attorneys for KBR reacted angrily to inquiries about the documents. In a letter urging The Times to "refrain from publishing" material under court seal, attorney Michael L. Rice also warned that the paper might be subject to unspecified legal sanctions.

KBR officials declined to be interviewed. In the past, they have said that the Army was responsible for selecting convoy routes and providing adequate protection.

Scott Allen, a lawyer for the families, confirmed that he had sent a letter to the Justice Department, but declined further comment and advised the families and surviving drivers to avoid interviews. A department spokesman acknowledged receiving the letter but also declined to comment.

The documentary record, though incomplete, provides the first behind-the-scenes look at a day when military goals clashed with corporate responsibilities, with soldiers and civilian truckers in the middle.

What follows is an account of the Good Friday convoy attack, based on the e-mails, court records and interviews.