Deadly Navy training accident at Fort Knox

Updated at 11:43 a.m. ET

LOUISVILLE, Ky. A U.S. Navy sailor was killed and five were injured during a training exercise at Fort Knox in Kentucky, a Navy spokesman said Friday.

Lt. David Lloyd, a spokesman for the Naval Special Warfare Group Two in Virginia Beach, Va., said the six sailors were riding in a Humvee as part of a convoy on the post when the accident occurred Wednesday night about 9:30 p.m. EDT.

Lloyd said the cause remains under investigation.

Five sailors sustained minor injuries and were treated and released from a hospital, he said.

The sailors were part of Naval warfare simulations taking place on the post. Lloyd called it "tactical training," but said the details are considered sensitive and could not be released.

Lloyd said the name of the deceased sailor may be released later Friday.

Naval Special Warfare Group Two oversees a variety of operations, including reconnaissance and counterterrorism. The Navy SEALS fall also fall under the Special Warfare Group's operations, though Lloyd did not say whether the wounded sailors were SEALS.

The U.S. Navy has used the 170-square-mile Fort Knox as a training ground since World War II. The Army post is about 50 miles southwest of Louisville and is home to about 14,000 military personnel, including active duty members and reserves.

It houses the Army's Human Resources Command and the 3rd Brigade Combat Team of the 1st Infantry Division. It was previously home of the U.S. Armor Center, but after 70 years at Fort Knox, the armored divisions were moved to Fort Benning in Georgia.

During World War II, naval architects tested mock-ups of ships at the inland post before the actual vessels were used in combat.

The Navy had five units and about 247 sailors involved in external training support at the post in 2011.

Kentucky's Salt River runs through the Army base. According to the Federal Register, the Corps of Engineers considers sections of the Salt River that fall within Fort Knox to be danger zones.

The river is used almost year-round for training and live fire exercises involving artillery, M1A2 Abrams Tanks, Bradley Fighting Vehicles, helicopters and other weapons systems. Public access to the area is barred because there may be unexploded ordnance from military weapons.

According to the Navy News Service, the Navy also uses the Salt River, a major Ohio River tributary, to shoot recruiting videos.