When U.S. soldiers invaded Iraq in 2003, they discovered huge ammunition dumps but left many of them unsecured. Today, American explosives experts are still destroying weapons stockpiles hidden around the country, and materials looted from them are still being used for roadside bombs, the No. 1 killer of U.S. troops.
About 450,000 tons of captured ammunition - mostly artillery, mortar and tank shells - have been destroyed so far, according to the Army Corps of Engineers. Even so, the flow of munitions to insurgents hasn't stopped, and coalition forces find new arms caches virtually every week.
At the beginning of the war, American forces didn't stop to secure or destroy the weapons dumps they found because there simply weren't enough troops, plus the insurgency hadn't started. Many military planners expected Iraqis to welcome U.S. troops as liberators and a friendly government to take over soon.
The American military started to destroy the hidden munitions in July 2003, as the insurgency began. The task was enormous from the start.
Iraqi dictator Saddam Hussein "was burying stuff all over the countryside," said Bill Sargent, the manager of the Army Corps of Engineers' Coalition Munitions Clearance Program, which is in charge of destroying the hidden ammunition.
The effort has cost about $1 billion and more than 18 million hours of labor so far. How much ordnance remains undiscovered is anyone's guess, officials said.
The program has included nearly 1,200 private contractors, more than 1,500 Iraqi workers and 10 U.S. government employees. Most of their work focused on destroying the ammo stocks at six large munitions depots. American troops were left to secure and destroy the smaller sites, which may have numbered more than 10,000, according to some estimates.
"I think there's just so many sites that nobody knows where they're all at," Sargent said.
About 105 substantial sites - each containing at least 100 ammunition-storage bunkers - had been found in Iraq by mid-October 2003, according to a briefing in Baghdad at the time. In one northern sector alone, U.S. troops found nearly 1,100 weapons and ammo caches in the first seven months of the war.
Some American military officers conceded that there weren't enough U.S. and coalition troops in Iraq to secure all the materiel stockpiles they'd found.
"There are so many weapons caches all over this country," said one officer, who asked not to be named at the time because he was speaking critically of American policy. "There are not enough troops. We don't have enough troops to guard them."
Demolition work at the six large depots wrapped up last March when contractor teams working for the Army Corps of Engineers blew up 248 tons of ammunition. They've turned over 19,000 tons to the Iraqi army and are training Iraqi soldiers in ordnance maintenance and disposal at a site north of Tikrit, the only one of the six large depots that will remain open. Smaller contractor teams have fanned out to work at another 25 to 30 sites around Iraq.
Their efforts have made it much harder for insurgents to obtain explosives, Sargent said.
"We've taken out a lot of stuff, and it's getting harder for them," he said. "They really have to go out and hunt for it now."
However, the insurgents continue to make bombs. Attacks with homemade bombs have nearly doubled since January, according to information obtained from U.S. officials.
Statistics compiled by the American-led military command in Baghdad indicate that 1,482 incidents with improvised explosive devices - as the military calls homemade bombs - were recorded in January. Of those, 834 exploded and 620 were found and cleared before they went off; 28 were found to be hoaxes.