HUSAYBAH, Iraq, April 19, 2005 -- Marine Lance Cpl. Joshua Butler shook himself from the rubble of a suicide truck bombing. He staggered to the ledge of his three-story guard tower and stared into a cloud of white smoke.

Butler, 21, of Altoona, Pa., was temporarily deafened by the blast, but he recalled what came next with cinematic clarity. The white smoke parted to reveal a clean red fire engine. It sped past a mural bidding travelers "Goodbye From Free Iraq" and hurtled directly toward Butler, who shot at the fire engine until it exploded about 40 yards away from him.

This true-life nightmare occurred on Monday last week. The attack on this remote Marine outpost abutting the Syrian border caused only minor injuries, but it signaled a dramatic change in the methods of the insurgents, who have staged mostly guerrilla-style hit-and-run attacks against the U.S. military for two years.

In interviews and in after-action reports, Marines who successfully defended the base that morning described a sophisticated assault that involved 50 to 100 insurgents.

The insurgents distracted Marine guards with well-aimed mortars and rocket-propelled grenades, then launched three successive suicide bombing strikes in an attempt to blow up the base and overrun it. The fire engine had a driver, a spotter and a bulletproof windshield, and was packed with dozens of propane tanks filled with explosives. The blast rained jagged red shrapnel for more than a minute, and unhinged doors and cracked the foundation of buildings well inside the Marine base.

The attack "demonstrates an extremely mature and capable insurgency," said Maj. John Reed, executive officer for the 3rd Battalion, 2nd Marine Regiment, which commands U.S. troops here. "It showed its ability to mass a very complex attack very quickly."

The attack, along with a similar assault on April 2 against the U.S.-run Abu Ghraib prison in which 44 American soldiers were wounded, presents a new challenge for the U.S. military, which is seeking to wear down the insurgency before transferring security responsibilities to U.S.-trained Iraqi forces. American commanders have expressed optimism that the insurgents, while far from defeated, have been significantly degraded as a fighting force; they said attacks have been less frequent and less effective since Iraq's Jan. 30 elections.

The number of attacks each day in cities such as Baghdad and Mosul has dropped by as much as 50 percent. Until recently, those attacks had largely been with roadside bombs and suicide car bombs aimed at platoons of U.S. military vehicles that conduct hundreds of patrols each day.

U.S. commanders said they interpreted the attack here as a desperate attempt by insurgents to reenergize the conflict. "I think they're losing, so they're looking at the big attacks to gain some momentum back," said Marine Capt. Frank Diorio, commander of India Company at Camp Gannon, the Marine base near the city of Qaim on the border with Syria. "I give them credit it for it; they're looking for a big score. We're going to see this a lot more. But now we know so we can address it."

Husaybah is a dusty smuggling hub in the barren reaches of western Iraq, a desert moonscape of dirt and rocks, its visibility frequently obscured by sandstorms. Camp Gannon is situated in the city's northwest corner.

The base's northern perimeter is the Syrian border, marked by a 10-foot-tall barrier of sand bags and razor wire. To the south and east are low-slung concrete houses and unpaved streets, neighborhoods so hostile the Marines cannot venture into the city without being attacked. The austere base is shelled so frequently the Marines never leave their barracks without helmets and armored vests, even when visiting the urinals -- mortar tubes hammered into the ground.

Opening Salvo

The battle here began around 8:15 a.m., shortly after India Company's 2nd Platoon set up for guard duty on the base's eastern perimeter. Four mortar rounds overshot the base and landed about 300 yards inside Syrian territory, said Cpl. Roy Mitros, the senior Marine on guard, who climbed into a tower to register where they landed.

Inside Post 8, a bunker on the southeast corner of the base, Lance Cpl. Joe Lampe, 22, of Lacey Township, N.J., and Cpl. Anthony Fink, 21, of Columbus, Ohio, began to receive reports that other guard positions were taking sporadic fire. Then, at 8:25 a.m., a rocket-propelled grenade slammed into their bunker.

Lampe and Fink were unharmed, but the bunker filled with dust from dozens of protective sandbags. "You couldn't see like an inch in front of us," Lampe said. "It's like it just went 'whoof,' and then it was just dust collapsing all around us."

Moments later, Lance Cpl. Diego Naranja, 22, of the New York City borough of Queens, radioed from a guard tower just north of Post 8 that he had spotted a white dump truck moving north on a one-lane road the U.S. military calls West End. "But as soon as he called it in, it was like, Blam!" Lampe said. "That's when we got hit by another blast. That one knocked us to the ground."

Fink said he was convinced that the insurgents concentrated fire on Post 8 as a diversion. "There's no doubt in my mind," he said. "They knew that was the closest post to them. If they could keep us down, then they could pull the [explosives-laden vehicles] out onto the road." Naranja said he managed to shoot several rounds at the dump truck but it soon disappeared.

The dump truck reached a fork, then turned west. It traveled beneath four concrete arches and sped toward the base, located next to the border crossing. The U.S. military closed the border for security reasons before the January elections and has not reopened it. The area is now a ghost town of abandoned customs and insurance houses and a 30-foot concrete mural painted with the Iraqi flag.

The dump truck headed directly toward Butler, who was standing guard under camouflage netting in Tower 2. Butler opened fire, and the truck veered left, ramming a cluster of trucks the Marines had wired together to block access to the base entrance. The dump truck then exploded, sending Butler flying into the tower's ledge as concrete debris rained on him.

Camp Gannon was now under full-scale attack. Mortars and rockets pelted the base from the south and east as most of the Marines, still in bed, scrambled toward the safety of bunkers.

About 45 seconds after the dump truck exploded, its purpose became clear: It was to serve as a battering ram to clear the base entrance for the fire engine.

The firetruck had become something of a phantom for India Company. The Marines had heard that insurgents might use one as a suicide bomb. For two months, they had been warned by commanders to be on the lookout for a firetruck, but it had never been seen and some Marines had concluded it wasn't real.

Now, the fire engine was roaring north along the West End. "When I seen it, my heart stopped," said Lance Cpl. Sebastian Lankiewicz, 20, also of Queens. "It was like I was looking at the Grim Reaper himself coming down freakin' West End."

The fire engine followed the same route the dump truck had taken, turning left at the fork, going beneath the arches and roaring toward the entrance to the base. Butler, who had staggered to his feet, could hear it before he could see it, the whining diesel engine getting louder behind a cloud of smoke.

"It was like a movie," he said. "It reminded me of 'Lethal Weapon.' The smoke was all there and then he just rolled through it, just like in the movie." Smoke "just rolled off the windows. I couldn't believe what was happening."

Suddenly it was upon him, and Butler could see inside the vehicle. "It had two individuals in it," he said. "They were dressed in all black, and their faces were veiled and covered. I could see the slits of their eyes."

Butler fired approximately 100 rounds at the firetruck. Like the dump truck, it turned left just before reaching the entrance. Butler said he thought the driver was either distracted by the withering fire or was unable to locate the entrance.

The sound of the explosion was "really unexplainable, just the noise and the violence about it," said Diorio, the company commander. Although the fire engine had failed to penetrate the entrance, "they were basically inside our perimeter," he said. The blast was so loud, Diorio feared the worst.

Slowly the reports began to filter in over the platoon network.

"Second platoon all accounted for."

"Third platoon all accounted for."

"Fourth platoon all accounted for."

"Thank you, Lord," Diorio whispered to himself.

"They were definitely close enough to cause a lot of damage," he said. "It was where they detonated it: It was a miracle. If I had to pick a place for them to detonate a firetruck full of explosives, if I had to pick one, I would have picked that place."

'Welcome to Iraq'

The vehicle exploded near the "Welcome to Iraq" mural, which absorbed some of the blast. So did a huge corrugated metal overhang that had provided shade for vehicles waiting in line at the border. It was obliterated, along with a low-slung blue-and-white building that also took some of the blast.

Only three Marines were wounded, none seriously. A piece of shrapnel pierced Butler's plastic goggles but did not penetrate the helmet they were attached to.

First Sgt. Don Brazeal, 39, of Riviera Beach, Md., was inside the company command post when the firetruck exploded. He had also feared the worst and rushed out to the base perimeter. "It's kind of a parental instinct that took over," he said. "A lot of these guys are young enough to be my sons. Right away I had a mental picture that my kids were not in a good way."

Brazeal arrived at Post 8 to find Fink firing at about a dozen insurgents. They were shielded by a wall on the other side of the road.

Brazeal grabbed a rocket launcher and climbed atop a dirt barrier, exposing himself to enemy fire. He fired the rocket at the wall. Fink then did the same. Then the shooting stopped, they said.

For nearly an hour, mortars and RPGs -- Marines estimated as many as 30 -- pelted the base. The unit summoned F-18 fighter jets and Cobra helicopter gunships; the Cobras fired machine guns and Hellfire missiles at what an after-action report described as vehicles transporting weapons. The small-arms fire around the base subsided at 9:30 a.m. but continued sporadically for nearly 10 hours.

The Marines said 19 insurgents were killed and 15 were wounded during 24 hours of fighting. An unknown number of civilians were also reported killed.

This week, the city remained tense. The Marines believed they had scored a decisive victory, tempered only by the realization that they faced an adversary perhaps more sophisticated than they had known.

"These guys knew what they were doing," said Lt. Ronnie Choe, 25, of Los Angeles, the battalion's assistant intelligence officer. "These weren't just random guys who decided: Hey let's do something."

© 2005 The Washington Post Company