Portrait of a US combat casualty

For Spc. Brett Christian, the morning of July 23 began ordinarily enough. He brushed his teeth and shaved. Then, climbing into the cab of his 21/2-ton diesel troop carrier not long after sunrise, the young soldier pulled into an Army convoy headed west out of the northern Iraqi city of Mosul.

Specialist Christian's mission was routine. He and a couple of dozen other troops from the 101st Airborne Division were bound for a firing range to zero their weapons. As was his habit, the gregarious 27-year-old was trading jokes in the cab. In the turret behind him, the machine gunner scanned flat brick rooftops and dusty streets.

The five-vehicle convoy rumbled past some charred chassis and artillery shells cluttering a scrap-metal dump - the kind found on the outskirts of many Iraqi cities - and began rolling up a hill.

Then, mid-joke, Christian's world exploded.

"As we crested the hill, I felt myself get hit with a bunch of glass and debris," says Lt. Christopher Wood, who was sitting next to Christian in the cab. "I thought we were getting ambushed, so I turned to tell Christian to put on the gas. He was already dead."

A standard mission. A sudden blast. A soldier lost - and no enemy in sight.

This is the kind of faceless battle that tens of thousands of US troops are bracing for in Iraq each day. For infantrymen like Lieutenant Wood who fought their way to Baghdad to topple the regime of Saddam Hussein, today's terrorist-style ambushes are in some ways worse than major combat, when the enemy was more visible and predictable. More than 52 US servicemen have died in hostilities since heavy fighting was declared over on May 1.

"There's a tangible air of frustration," says Wood, whose hearing was impaired and left eye injured in the ambush. Six other soldiers suffered shrapnel wounds.

The Mosul region, after a period of relative quiet, has experienced a spate of attacks since the 101st joined with other US forces to surround and kill Uday and Qusay Hussein on July 22. Military intelligence officers are unsure exactly who the enemy is, but say strikes have grown in sophistication. That some motivated by cash or revenge are willing to attempt the attacks is no surprise, they say. As in many places in Iraq, this city of 2.3 million people is home to thousands of unemployed young men and ingrained patterns of violence: Gunfire erupts here nightly and residents fish in the Tigris River using hand grenades.

To be sure, US forces are aggressively flushing out weapons, money, and potential attackers while also scrutinizing their methods. In recent days, for example, soldiers with the 101st foiled a rocket-propelled grenade (RPG) ambush and uncovered caches of missiles and hundreds of RPGs and rounds of ammunition. Troops are also becoming more skilled at identifying and disabling the kind of improvised explosive device that killed Christian. For every deadly attack, many more fail.

Meanwhile, soldiers such as Wood who survive close calls are carrying on with their jobs - driven variously by duty, resentment, and the knowledge that they have no choice.

Inside a heavily fortified Mosul hotel that was gutted by looters before his infantry company moved in, Wood speaks about the attack - even its first desperate moments - with a tone of detached resignation.

Moments after the makeshift blast - most likely from artillery shells planted in the road median and ignited remotely by a waiting enemy - Wood struggled to see clearly and get his bearings. The troop truck kept rolling forward but Wood could not reach the brakes.

"We gotta get out of here!" the gunner yelled, kicking Wood in the back. So Wood bailed out and with the rest of the troops took up fighting positions. The gunner, in a state of shock, sprinted from the scene and off the road. Other soldiers found him 50 meters away, and he was later evacuated from Iraq - a casualty of mental more than physical trauma.

Indeed, two days later, a group of Christian's comrades from the 2nd Battalion, 502nd Infantry Regiment met for hours with a combat-stress team sent to help them vent their grief rather than bottle it up. "For them, it was like losing a family member," said Lt. Col. David Lonnquist, a combat-stress expert with the 113th Medical Company.

Some soldiers cried, and others raised doubts. "There were a lot of questions like 'What are we doing here?'" Colonel Lonnquist said. "That's not clear to some people, whereas it is clear in combat."

Back home in Cleveland, Christian's mother, a single parent, was mourning, too. On hearing a radio report of the attack, Tess Christian knew intuitively her oldest son was gone. "It's such a gut-wrenching feeling," she told a local newspaper. He died on her birthday.

The attack also weighed on the minds of Wood and his men as they set out soon afterward on a night foot patrol in an anti-American neighborhood of Mosul. Wastewater ran in gutters through the narrow streets, and children emerged from dim alleys to throw rocks at the soldiers. Once, orange tracer rounds flew up from behind a building. Nearby, a man on a rooftop peered down at the patrol.

"That makes me uncomfortable as hell," Wood said as he glanced around, his one eye bloodshot from the attack.

"I never trusted the population before and I'm even less trustful now and somewhat resentful," he says. "We removed a totalitarian regime and are trying to set up a democracy, and still people want to do us harm.

"I can't understand it. But," he added, "it's not for me to understand."

It was already hot at 8:00 a.m the next day, when Christian's fellow soldiers gathered at their Mosul camp to bid him farewell. Sunlight filtered through a camouflage awning, dancing on their shoulders. Before them stood a shrine of Christian's boots, rifle, and helmet, along with his Bronze Star and a snapshot of him in his truck.

"We shouldn't put question marks where God puts periods," said Chris tian's company commander, Capt. John Yorko, as if reading the men's minds.

One of Christian's closest buddies, Spc. Nathan Galante, recalled his friend's infectious humor as well as his bravery, shown when he took the lead in a convoy of trucks that came under small-arms fire during the war. "We love you, Brett," he said.

Then the company's burly first sergeant led roll call, summoning Christian by his new rank of sergeant. He was due for promotion Aug. 1.

"Sergeant Christian...." he called out hoarsely.

"Sergeant Brett Christian.....

"Sergeant Brett Thomas Christian...." Shots broke the silence, and the sound of taps rose over the rooftops of Mosul.