After an unusual delay the Pentagon on Thursday released the names of the 30 American servicemen killed Saturday when their Chinook helicopter was apparently hit by a rocket-propelled grenade and crashed in Afghanistan.

It was the deadliest attack on U.S. forces in the decade-long war in the country.

Twenty-five of the Americans killed were special operations forces, and five were Army aircrew members, the Pentagon said. Seven Afghan commandos and an Afghan interpreter also were killed. Also killed was Maui resident Kraig Vickers, a Navy explosives expert.

The release of names, ranks, ages, hometowns and units of those who die or are killed in combat zones is standard practice by the Pentagon.

According to the Pentagon, Defense Secretary Leon E. Panetta decided to identify the servicemen after considering security concerns raised by U.S. Special Operations Command.

Recalling the fallen

The Pentagon released the following casualty information on Thursday:

Navy sailors assigned to an East Coast-based Naval Special Warfare unit who were killed:

Lt. Cmdr. (SEAL) Jonas B. Kelsall, 32, of Shreveport, La.

Special Warfare Operator Master Chief Petty Officer (SEAL) Louis J. Langlais, 44, of Santa Barbara, Calif.

Special Warfare Operator Senior Chief Petty Officer (SEAL) Thomas A. Ratzlaff, 34, of Green Forest, Ark.

Explosive Ordnance Disposal Technician Senior Chief Petty Officer (Expeditionary Warfare Specialist/ Freefall Parachutist) Kraig M. Vickers 36, of Kokomo, Hawaii

Special Warfare Operator Chief Petty Officer (SEAL) Brian R. Bill, 31, of Stamford, Conn.

Special Warfare Operator Chief Petty Officer (SEAL) John W. Faas, 31, of Minneapolis

Special Warfare Operator Chief Petty Officer (SEAL) Kevin A. Houston, 35, of West Hyannisport, Mass.

Special Warfare Operator Chief Petty Officer (SEAL) Matthew D. Mason, 37, of Kansas City, Mo.

Special Warfare Operator Chief Petty Officer (SEAL) Stephen M. Mills, 35, of Fort Worth, Texas

Explosive Ordnance Disposal Technician Chief Petty Officer (Expeditionary Warfare Specialist/Freefall Parachutist/Diver) Nicholas H. Null, 30, of Washington, W.Va.

Special Warfare Operator Chief Petty Officer (SEAL) Robert J. Reeves, 32, of Shreveport, La.

Special Warfare Operator Chief Petty Officer (SEAL) Heath M. Robinson, 34, of Detroit

Special Warfare Operator Petty Officer 1st Class (SEAL) Darrik C. Benson, 28, of Angwin, Calif.

Special Warfare Operator Petty Officer 1st Class (SEAL/Parachutist) Christopher G. Campbell, 36, of Jacksonville, N.C.

Information Systems Technician Petty Officer 1st Class (Expeditionary Warfare Specialist/Freefall Parachutist) Jared W. Day, 28, of Taylorsville, Utah

Master-at-Arms Petty Officer 1st Class (Expeditionary Warfare Specialist) John Douangdara, 26, of South Sioux City, Neb.

Cryptologist Technician (Collection) Petty Officer 1st Class (Expeditionary Warfare Specialist) Michael J. Strange, 25, of Philadelphia

Special Warfare Operator Petty Officer 1st Class (SEAL/Enlisted Surface Warfare Specialist) Jon T. Tumilson, 35, of Rockford, Iowa

Special Warfare Operator Petty Officer 1st Class (SEAL) Aaron C. Vaughn, 30, of Stuart, Fla.

Special Warfare Operator Petty Officer 1st Class (SEAL) Jason R. Workman, 32, of Blanding, Utah

The following sailors assigned to a West Coast-based Naval Special Warfare unit were killed:

Special Warfare Operator Petty Officer 1st Class (SEAL) Jesse D. Pittman, 27, of Ukiah, Calif.

Special Warfare Operator Petty Officer 2nd Class (SEAL) Nicholas P. Spehar, 24, of St. Paul, Minn.

Army soldiers killed:

Chief Warrant Officer David R. Carter, 47, of Centennial, Colo. He was assigned to the 2nd Battalion, 135th Aviation Regiment (General Support Aviation Battalion), Aurora, Colo.

Chief Warrant Officer Bryan J. Nichols, 31, of Hays, Kan. He was assigned to the 7th Battalion, 158th Aviation Regiment (General Support Aviation Battalion), New Century, Kan.

Sgt. Patrick D. Hamburger, 30, of Lincoln, Neb. He was assigned to the 2nd Battalion, 135th Aviation Regiment (General Support Aviation Battalion), Grand Island, Neb.

Sgt. Alexander J. Bennett, 24, of Tacoma, Wash. He was assigned to the 7th Battalion, 158th Aviation Regiment (General Support Aviation Battalion), New Century, Kan.

Spc. Spencer C. Duncan, 21, of Olathe, Kan. He was assigned to the 7th Battalion, 158th Aviation Regiment (General Support Aviation Battalion), New Century, Kan.

Air Force airmen killed:

Tech. Sgt. John W. Brown, 33, of Tallahassee, Fla.; Staff Sgt. Andrew W. Harvell, 26, of Long Beach, Calif.; and Tech. Sgt. Daniel L. Zerbe, 28, of York, Pa. All three airmen were assigned to the 24th Special Tactics Squadron, Pope Field, N.C.