The patrol has lasted an hour, the three humvees slashing and darting through hairpin turns and blind alleyways, looking for attackers. It's 9 o'clock on a clear, mild December night in Adhamiya, one of Baghdad's oldest neighborhoods and these days among the most restive. The soldiers are out to draw fire. They cruise the streets and make themselves targets in order to flush insurgents into the open.
But they encounter nothing. So now the convoy is heading back to base, a mile away. The platoon rolls into Adhamiya's main marketplace. The atmosphere is festive. Patrons of the teahouses and restaurants overflow onto the one-lane street. Traffic is running in both directions, and the convoy slows to a crawl. Just across Imam Street, the district's main thoroughfare, sits the Abu Hanifa mosque, where Saddam Hussein was last seen in public before his arrest by U.S. forces. A large crowd of Iraqis mills outside it. Private First Class Jim Beverly, 19, and Private Orion Jenks, 22, stand in the bed of the convoy's second vehicle, a roofless high-back humvee, which resembles a large pickup truck and is generally used to transport troops. Also riding in the back are two TIME journalists. As the convoy begins moving again, Jenks and Beverly chat casually and laugh. Sergeant Ronald Buxton, who is riding shotgun in the cab of the high-back, whips around. "I don't care if you joke or if you smoke," he tells the privates, "but make sure you watch our back."
The vehicles cross Imam Street and move toward the mosque. TIME senior correspondent Michael Weisskopf glances up at the mosque's clock tower, damaged by U.S. tank shells during a fierce battle in April. As he does, he hears a clunk and sees that an oval-shaped object has landed on the seat beside him. For a split second he thinks it's a rock, then he realizes it isn't. He reaches to throw it out. Suddenly there is a flash. The object explodes in Weisskopf's hand.
Shrapnel ricochets off the walls of the humvee, hitting Beverly, Jenks and TIME photographer James Nachtwey. Smoke rises from the high-back. Blood pours from Weisskopf's right arm; when he holds it up, he realizes the grenade has blown off his hand. Specialist Billie Grimes, a medic attached to the platoon, sprints out of the third humvee and hoists herself onto the high-back. She uses a Velcro strap tied to her pant leg as a tourniquet to stop Weisskopf's bleeding and applies a field dressing to the wound while loudly asking the three other passengers if they are injured. Nachtwey, who has taken shrapnel in his left arm, abdomen and both legs, briefly snaps pictures of Grimes treating Weisskopf before losing consciousness. For several seconds Jenks slumps motionless, stunned, but then instinctively slides his gun's safety to semiautomatic, preparing to return fire. Only later does he learn that shrapnel has fractured his leg.
The convoy halts in front of the mosque. Buxton turns around. "Are there any casualties?" he asks. "Yes! Yes!" replies Beverly. Shrapnel has hit him in the right hand and right knee. Two of his front teeth have been knocked out, and his tongue is lacerated. "Let's go!" he says. "Let's go!" The humvees peel out and roar for home.