GAINESVILLE, Ga. (Fortune Small Business) -- Benjamin Lichtenwalner remembers the first time he cleaned up the grisly remains of a military catastrophe.

Four years ago he was a U.S. Marine sergeant stationed in Ramadi, then a stronghold of the Iraqi resistance. Four U.S. servicemen guarding a corner of the American base camp had popped the hatch of their tank for some fresh air when they were hit by enemy fire. Three died.

"As far as the eye could see, there were body parts," Lichtenwalner recalls. "Everything from little pieces to entire torsos."

As a member of the Marines' mortuary-affairs unit, he was assigned to scrub the outdoor area, both for sanitary purposes and to maintain morale. "Everything had to be taken up," he says. "What if a fallen serviceman's buddy came rolling through, leaned over to tie his boot and saw something that we missed?"

Lichtenwalner, 28, and his partner, Ryan Sawyer, 25, became intimately familiar with death. It was their job to prepare the bodies of their late comrades for their final ride home. This experience also helped inspire Biotrauma, the crime-scene cleanup business they started in Gainesville, Ga., in 2006, soon after their discharge from the Marines.