ARAB JABOUR, Iraq -- From the blast and the high, thin plume of white smoke above the tree line, it looked and sounded like any other attack. The bare details were, sadly, routine enough: A gunner was killed and three crew members were wounded Saturday when their vehicle rolled over a homemade bomb buried beneath a road southeast of Baghdad.
Yet, it was anything but routine. Over a crackling field radio came reports of injuries and then, sometime later, official confirmation of the first fatality inflicted by a roadside bomb on an MRAP, the new mine-resistant ambush-protected armored vehicle that the American military is counting on to reduce casualties from roadside bombs in Iraq.
The military has been careful to point out that the new vehicle is not impervious to attack and that a sufficiently powerful bomb can destroy any vehicle. Still, a forensic team was flown in immediately to inspect the charred wreckage, from which wires and tangled metal protruded, to determine whether the bombing had revealed a design flaw.
"It's a great vehicle, but there is no perfect vehicle," said Lt. Col. Kenneth Adgie, commander of the battalion that lost the soldier.
Three of the four people aboard suffered broken feet and lacerations. Pending the results of an investigation, it is unclear whether the gunner was killed by the blast or by the vehicle rolling over.
But officers on the scene noted that he was the member of the crew most exposed and that the vehicle's secure inner compartment was not compromised and appeared to have done its job by protecting the three other crew members inside.
"The crew compartment is intact," said Capt. Michael Fritz. He said the blast would have been large enough "to take out" a heavily armored Bradley fighting vehicle.
Roadside bombs have been the single deadliest weapon that insurgents have directed against U.S. forces in Iraq and have grown increasingly sophisticated and powerful over the years.
The MRAP vehicles have distinctive, armored V-shaped hulls that are designed to deflect the force of the explosion from roadside bombs out and away from the vehicle, sparing the occupants in the compartment.
The underbody sits about 36 inches off the ground, higher than the Humvees that have proved susceptible to roadside bombs despite the addition of armor to many of them in combat zones.
The new vehicles are much bigger than Humvees, standing 12 feet tall; weighing up to 18 tons; carrying six to 10 soldiers, depending on the model; and costing an average of $500,000 apiece and up to $1 million. There are more than 1,500 of them in Iraq, and the military plans to buy more than 20,000 of them at a total cost of more than $10 billion.
Saturday's deadly attack came on the first day of an operation to clear insurgents from southern Arab Jabour, a rural, overwhelmingly Sunni area less than 10 miles southeast of Baghdad on the Tigris River. The primary target is al-Qaida in Mesopotamia, the homegrown extremist group that American intelligence says is foreign-led.
The bomb went off at 4:45 p.m., as engineers were driving beside an irrigation ditch to support soldiers of the 1st Battalion, 30th Infantry Regiment, 2nd Brigade Combat Team, 3rd Infantry Division, who had been clearing farmhouses and villages since a dawn air assault. The blast threw the vehicle into the air and spun it 180 degrees, with its shattered nose coming to rest beside the ditch.
Several vehicles in the convoy had already passed over the same spot but failed to trigger what officers believe was a deeply buried homemade bomb, which the military calls an improvised explosive device, or IED, made from about 300 pounds of fertilizer and triggered with a pressure device.
Infantrymen who had spent the day carefully maneuvering on foot through fields and ditches heard the blast and saw the smoke.
"That was another IED," said Capt. John Newman, the commander of Company B, to groans from his men who had walked close to the blast site earlier that morning.
Two minutes later came another report. "It was an MRAP, totally destroyed," said the radio operator.
Two rescue helicopters arrived minutes later to evacuate the wounded.
Dismayed, their colleagues carried on with their patrols, detaining insurgent suspects and searching for other bombs in farmyards and vehicles.