SAVANNAH, Ga. — A U.S. soldier grievously wounded in a suicide bombing two years ago in Afghanistan filed suit Wednesday against an American defense contractor that employed the bomber, saying it failed to supervise the man as he built an explosive vest on the job using the company's tools and parts.

The federal lawsuit by 22-year-old Army Spc. Winston Hencely accuses Fluor Corporation of allowing the Afghan national responsible for the bombing to work alone and to skip an escort off Bagram Air Base on the morning of Nov. 12, 2016.

About an hour after his work shift ended, Ahmad Nayeb detonated his vest on the base and killed himself along with three U.S. soldiers and two fellow Fluor employees. Another 16 people, including Hencely, were wounded.

"Fluor's negligent supervision of the bomber enabled the bomber's attack against the Army," said the lawsuit filed in U.S. District Court in Greenville, South Carolina, one of Fluor's U.S. locations. It added that "Fluor well knew that in Afghanistan, and on American military bases in particular, suicide bombers were a constant and dire threat."

The lawsuit seeks unspecified monetary damages against the company.

A Fluor spokesman, Brett Turner, said Wednesday that the company had no immediate comment.

The company was responsible for upkeep of non-tactical vehicles at Bagram at the time of the attack. Nayeb worked in the vehicle yard, disposing of motor oil and other potentially hazardous automotive materials.

Hencely of Springfield, Georgia, was deployed to the U.S. base in Afghanistan as a soldier in the Army's 1st Cavalry Division. Soldiers were gathering for the start of a Veterans Day foot race, the lawsuit says, when Hencely noticed Nayeb and thought he looked suspicious. The soldier grabbed Nayeb, who detonated an explosive vest beneath his clothes.

An Army investigation later found that a "lack of reasonable supervision facilitated Nayeb's ability to freely acquire most of the components necessary for the construction of the suicide vest and the freedom of movement to complete its construction," according to the military's 2017 report on the bombing.

Nayeb smuggled explosive materials used in his suicide vest onto the U.S. base, the lawsuit said, and completed it during his work shifts using string and an electrical switch from the Fluor work site as well as nuts and bolts used for shrapnel. Fluor staffers also allowed the bomber to check out a multimeter used to measure electrical currents, though the tool wasn't needed to perform his job.

Hencely suffered serious brain injuries and shrapnel wounds to his chest from the blast. The lawsuit says he has permanent short-term memory loss, has suffered seizures and remains unable to fully use his hand, arm and leg on his left side. Hencely remains in the Army while recovering at home in Georgia.

"He likely will never be able to cook for himself because he would forget that he put food on the stove," the lawsuit said. "He likely will never be able to live alone and may require full-time live-in care for the rest of his life."

This article was written by Russ Bynum from The Associated Press and was legally licensed through the NewsCred publisher network. Please direct all licensing questions to legal@newscred.com.