An Army investigation into the Iraqi ambush that made Pfc. Jessica Lynch (search) a household name has concluded she was gravely injured when her military vehicle crashed -- and not by Iraqi gunfire, officials said.

The Army on Thursday was scheduled to release a detailed 15-page report on the March 23 ambush in Nasiriyah (search) in which 11 members of Lynch's 507th Maintenance Company (search) were killed and seven, including Lynch, 19, were taken prisoner in what became the most famous battle of Operation Iraqi Freedom.

In the report, investigators from the Army's Training and Doctrine Command (search) are expected to detail a series of tragic mistakes -- including an exhausted commander picking the wrong route, failed radio communications and poorly maintained rifles that jammed in the heat of battle -- that led Lynch's 13-vehicle convoy to veer helplessly into an area still controlled by Iraqi security forces, according to Pentagon officials familiar with the findings.

But it will not make any recommendations for discipline, blaming the circumstances on fatigue and "the fog of war," adding that soldiers of the unit did their duty and "fought as best they could given the situation."

The report will also shoot down a legend that emerged shortly after Lynch's rescue that the West Virginian teen emptied two guns on Iraqi soldiers before she was shot, stabbed and captured, military officials said.

The report will say the speeding Humvee in which Lynch was riding with other soldiers was most likely struck with a rocket-propelled grenade that caused it to lose control and smash into a disabled tractor-trailer rig.

The driver of the Humvee, Lynch's good friend Pfc. Lori Ann Piestewa of Tuba City, Ariz., died in an Iraqi hospital of injuries she suffered in the accident.

The company's senior enlisted soldier, 1st Sgt. Robert Dowdy, was also in Lynch's Humvee and had worked heroically to reorganize the convoy after the ambush began and even rescue two soldiers from a disabled truck.

He died instantly when the Humvee was hit by the grenade as the convoy was trying to get away, the report will say.

Lynch was rescued a week later in the same hospital in which Piestewa died in a dramatic raid by elite forces.

The report stated the company commander, Capt. Troy King, charted the wrong course for the convoy to travel on its dash from Camp Virginia in Kuwait toward Baghdad, taking the convoy directly into Nasiriyah at a time when it was still under Saddam Hussein's control, rather than making a turn.