-- The truck roared up in a blizzard of white dust, its wheels spinning in the fine powder that covered the fenced-in lot known around here as the "BLAHA." The driver was in a hurry. The drivers were always in a hurry, and the Marines running the lot knew that without asking.

A forklift operator began moving stacks of 155mm artillery rounds onto the truck. A short distance away, Lance Cpl. Jorg Lozano and Pvt. Timothy Haney each grabbed a 112-pound box of mortar shells and hoisted it onto a stack of wooden crates. They walked so fast that the dust kicked up by their boots covered them like a swarm of bees.

"Sometimes it's so busy we have to load the ammo by hand," said Lozano, 19, of Laredo, Tex. "But I know I keep the blood flowing."

"What makes the blood flow, Lozano?" asked Cpl. Johnathon Castille, 21, of Lafayette, La., drilling the junior Marine.

"Ammo," Lozano replied. "Ammo, ammo," Haney said, chiming in, until the only sound in the yard was the two Marines chanting "ammo, ammo."

Since the battle of Fallujah started one week ago, few places at this main Marine outpost near the city have been as busy as the BLAHA, an Army acronym borrowed by the Marines that stands for "Basic Load Ammo Holding Area." When the artillery batteries need canon and mortar shells or the troops on the front line need flares and grenades, this is the place their supply groups come for ammunition.

Because of the large scale of the offensive operation, the ammo crews have been working nearly nonstop, trying to fill orders for U.S. and Iraqi security forces who continued Sunday to battle the last insurgent holdouts.

Most hours of the day and night, trucks line up, sometimes six to eight deep, waiting for ammo. The six Marines on duty rush around counting crates and boxes of mortar shells, smoke grenades and tank rounds, filling the orders and then loading them onto supply trucks.

"It's a big frigging ballet of forklifts," said 1st Lt. Ben Chase, 25, of New York City, a logistics officer for the 1st Marine Expeditionary Force Combat Service Support Battalion. Chase carried a tattered, green cloth-covered notebook with his favorite song lyrics scribbled on the back. "Fortified, Live, Reppin'. N.Y. Till I Die," one read. "One of us equals many of us. Disrespect one of us, you'll see plenty of us," read another.

"Everyone misses home out here," Chase said. "That's the worst thing. I can handle just about anything, but I miss New York City."

Lozano scurried by with his own notebook.

"Who's coming in?" Castille called after him.

"Twenty-fourth MEU," Lozano answered, referring to the 24th Marine Expeditionary Unit.

"How much they picking up?"

"A lot," Lozano replied, before rushing off.

The ammo yard is divided into cells, one for "demo," one for "arti" and another for "pyro." These stand for demolition, artillery and pyrotechnic rounds. Some of the units that collect their ammo have their own cells where they can store and pick up the pieces that they need without waiting in line. But most units come in through the front gate and wait as the Marines rush to fill their orders in an organized frenzy.

"Our mission here is get the customer out of here as fast as possible," Chase said. "Everyone needs it immediately. Everything is an emergency. I tell my Marines basically to run themselves ragged."

Because of the massive amounts of artillery lobbed during the Fallujah offensive, logistics officers have been scrambling to make sure their units are adequately supplied. Inventory is measured in colors: green, amber, red and black. Green is a full supply and black means the ammo stock is empty.

"At no time have we gone black, but there have been many times we were getting really, really close," said 1st Lt. Johnny Fortenberry, 31, a Task Force 2-2 soldier with the Army's 1st Infantry Division.

As he drove across the military post, Fortenberry received a call over the radio telling him that he could pick up more 155mm rounds at the BLAHA.

"Roger," Fortenberry said into the radio. "Please give me a call when you get a final count. Over."

Castille said the Marines and soldiers have favored the larger explosives for the Fallujah operation.

"They love the stuff that goes boom," he said, walking through aisles of grenades and mortar shells in a spacious warehouse stacked with small-arms ammunition. "It's safer to throw one of these things into a building and then they can go in after it's clear."

Haney said the Marines supplying the ammo feel that they are part of the battle, even if they aren't fighting the insurgents face to face.

"If they didn't have us, they'd be lost," he said. "They wouldn't be able to fight. I feel really a part of what's going on out there."

With that, he spit out the juice from the tobacco chew stuffed in his left cheek.

Above, Lance Cpl. Jorg Lozano, 19, of Laredo, Tex., stacks 112-pound boxes of mortar shells at the BLAHA, or Basic Load Ammo Holding Area. At left, a sign reminds troops to bring back their empty ammunition cans. "Sometimes it's so busy we have to load the ammo by hand," Lozano said.