He killed insurgents who were heavily armed and probably high on drugs — and who had just killed his close friend, Lance Cpl. Erick Hodges.

He protected two wounded squad members from attack and saved innumerable Marines.

When it was over, Adlesperger's face had been bloodied by shrapnel and he had bullet holes in the sleeve and collar of his uniform. He refused to be evacuated until Hodges' body was recovered.

For hours, they faced only minor resistance. A few more buildings and they could stop for the night.

"We had cleared buildings all day, hundreds of them, but on that 101st house, that's the one that gets you, and that's what happened," said [Gunnery Sgt. Paul] Starner, 33, a 14-year Marine veteran.

Like a lot of Iraqi buildings in the Jolan, the structure had a wall around it. There was a courtyard in front of the building and an outdoor stairway leading to the roof.

Adlesperger, acting as the point man for the four-man fire team, had attempted to knock down a gate. Hodges moved forward and was immediately felled by a hail of bullets from inside, probably from a concealed opening in the masonry wall.

As they rushed the house, Navy corpsman Alonso Rogero was hit in the stomach and Lance Cpl. Ryan Sunnerville in the leg. Grainy, shaky film of the incident shows Sunnerville hopping on one leg, still firing his M-16. Marines and insurgents exchanged gunfire from no more than 20 feet. From inside the building, the insurgents also threw grenades.

The insurgents had hoped to spring what is called a Chechen ambush, named after the rebels who have fought Russian troops for years. The tactic is particularly successful when tanks cannot be used.

The strategy, Marines determined later, had been to wound Marines attempting to enter the building. When other Marines came to help them, an insurgent sniper down an alleyway would pick off corpsmen, radio operators and officers. And when enough Marines or vehicles were gathered, insurgents would fire rocket-propelled grenades.

Adlesperger fired at the insurgent machine-gun position as he ran toward Rogero and Sunnerville. He helped the two up the outside stairway to the roof. As insurgents tried to storm the stairway, Adlesperger killed them before they could reach the roof. Shrapnel ripped into his face.

From his rooftop position, he could see insurgents peppering Hodges' lifeless body with bullets, including two to his head. When one ran from the building to seize Hodges' weapon, Adlesperger killed him with a single shot.

Still, the machine-gun position inside the building had not been touched, and it was pinning down Marines gathering to assault the building from the front. With no time to consult officers, and with other Marine units engaged in firefights, Adlesperger was left to his own initiative.

"Chris essentially took over," said [Col. Patrick] Malay.

Unable to penetrate the building with his M-16, Adlesperger shifted to the grenade launcher. Standing on the roof, he blew holes in the building and then rained down gunfire on the insurgents below him. They returned fire and then fled.

From his rooftop position, Adlesperger killed four insurgents who had fled into the courtyard, each with a shot to the head. By Malay's estimate, Adlesperger killed a total of 11 insurgents. The actual number may be higher.

The building had been an insurgent command-and-control center. Failure to quickly subdue it, Malay concluded, could have thrown off the timetable for the Fallouja assault, which depended on speed and keeping U.S. casualties to a minimum.

Marines from adjoining rooftops joined Adlesperger and began preparing the wounded for evacuation. Once that was done and Hodges' body was removed, the Marines pushed in one side of the building with an amphibious assault vehicle. Adlesperger insisted on being the first Marine to search the building to make sure all the insurgents were dead.

That night, Starner went to Adlesperger to gather information for the official report. As Adlesperger spoke, he began to weep — not for the men he had killed, or even for the fact he had had to kill them, but for Hodges, a wisecracking Northern Californian who was on his second combat tour in Iraq and had turned 21 only the day before.

"He just kept saying, 'Hodges, Hodges, we had to get him out,' " Starner said.

Adlesperger, Hodges and Sunnerville were particularly close. Each had been a high school wrestler, each had learned to trust his life to the others.

"We were tight," said Sunnerville, 22, who has recovered from his wounds, been promoted to sergeant and recently finished his third combat tour in Iraq.

Even for combat-hardened troops, Adlesperger's death was emotionally wrenching. In the midst of the fight to rid Fallouja of insurgents, Marines took time to mourn. Several later had his name tattooed on their arms.

"When we finally went firm [moved to a secure location], one of the noncommissioned officers cried all night about Chris, and I had to separate him from the other Marines," Starner said.

A member of Kilo Company wrote later in an online tribute to Adlesperger: "This is to you and your family, a sincere thank-you for letting all of us come home and live and love. But most importantly, showing us what sacrifice and being a true man is all about."

The night Adlesperger died, Malay went to the mortuary affairs unit at the Marine encampment in Fallouja to inspect his body, in part so he could tell the family how he died.

But that was not the only reason.

"It's a hard thing to explain, but somehow I just felt compelled to say goodbye," said Malay in a soft, slow voice during an interview in Carlisle, Pa., where he is attending the Army War College.

"He had a touch of greatness."

Much of the Marine philosophy about bravery can be found in the classic study "The Anatomy of Courage," published in 1945 by Lord Moran, a British physician who served at the front during World War I and then as physician to Winston Churchill for 25 years. The book is on a Marine Corps reading list given to sergeants on up through captains.

Moran's thesis is that men fight not just for survival or patriotism but in response to strong leadership — and because they have grown to identify with their group so tightly that any threat to the group is seen as intolerable.

Courage, Moran suggests, is a moral quality that comes from an unwillingness to quit. Fear, he says, is a critical part of it. Without fear, he argues, there is no courage; fear provides the energy, the resolve.