Criss-crossing Iraq, the hundreds of civilian truck drivers who form a "shadow army," hauling food and supplies to military bases, are a tempting target for attacks.
Ohio truck driver Robert Rowe, a former Marine, was shot while leading a convoy into Baghdad.
"We got hit from both sides, a guy on top of the bridge," Rowe says. "A round come through and tagged me in the leg."
Cindy Morgan was Robert Rowe's convoy commander. A rare female truck driver in Iraq, she's written a book about working in a war zone.
"We live, we eat, we sleep, pretty much side by side with our troops. And we get shot at, we bleed and we die beside them," Morgan says.
Since the war began, more than 600 civilians employed by American companies have been killed. More than 7,000 have been injured.
At $80,000 or more a year, they're some of the best-paid truck drivers in the world. But for some, even that big a reward doesn't justify the risk.
"A lot of them are like I am," Morgan says. "There's not enough money to go play Russian Roulette with your life."
West Virginia truck driver Brian Rolfe found his life on the line while driving a fuel tanker at night.
"I heard a pop and a glass crackling and then it felt like a 50-pound sledgehammer hit me upside the head," Rolfe says.
Somehow, he maintained control of his truck, even after taking a sniper's bullet in the head.
"When I feel a headache starting, it feels like a steel band being tightened around the base of your skull," Rolfe says.
Many of America's "shadow soldiers" find themselves suffering, but still proud of their decision to back our troops in Iraq.
"It gave you sense of pride. And if I could help out again, I'd do it," Rowe says. "I'd do it in a heartbeat."
Many of these civilian contractors told CBS News they fight a new battle when they come home. They have a difficult time collecting health benefits and worker's compensation for their physical and emotional injuries.