Of the seven U.S. service members killed since Operation Inherent Resolve began, two are airmen.

Capt. William Dubois, 30, was killed in December when his F-16 crashed shortly after takeoff from a base in the Middle East. Dubois, of New Castle, Colorado, was assigned to the 77th Fighter Squadron at Shaw Air Force Base, South Carolina.

Tech. Sgt. Anthony Salazar, 40, died of a non-combat-related injury on April 13. His death was under investigation as of April. Salazar was a native of Hermosa Beach, California. He was assigned to the 577th Expeditionary Prime Base Engineer Emergency Force Squadron, part of the 1st Expeditionary Civil Engineer Group.

The other service members:

Marine Cpl. Jordan Spears, 21, was the first service member who died supporting Operation Inherent Resolve. On Oct. 1, he was aboard an MV-22 that had just taken off from the assault ship Makin Island when the Osprey plummeted toward the water. Ordered to ditch, Spears jumped out of the Osprey, but he was weighed down by his body armor and sank after his life vest failed to deploy. His body was never found.

Marine Lance Cpl. Sean Neal, 19, died Oct. 23 in Baghdad in a non-combat-related incident. As of October, his death was under investigation. Neal, of Riverside, California, was on his first deployment. He joined the Marine Corps in July 2013 and was assigned to the 2nd Battalion, 7th Marines, at Twentynine Palms, California.

Navy Petty Officer 3rd Class Ryan Burris, 24, died May 21 in Zayed Military City, Abu Dhabi, United Arab Emirates in a non-combat-related incident. His death was under investigation as of May. Burris, of Lisle, Illinois, was temporarily assigned to the Crisis Response Element of Joint Special Operations Task Force-Arabian Peninsula, Special Operations Command Central, U.S. Central Command.

Navy Petty Officer 3rd Class Devon Doyle, 21, died May 16 when he fell from a balcony in Manama, Bahrain, while he was on liberty. Doyle, of Alamosa, Colorado, was assigned to the Mayport, Florida-based destroyer Farragut, which was part of the Theodore Roosevelt Carrier Strike Group.

Army Pfc. Monterrious Daniel, 19, died June 12 at Camp Buehring, Kuwait, in a non-combat-related incident. The Defense Department did not announce the cause of his death. Daniel, of Griffin, Georgia, was assigned to the 68th Combat Sustainment Support Battalion, 43rd Sustainment Brigade, 4th Infantry Division, at Fort Carson, Colorado. He joined the Army in April 2014 and deployed to Kuwait in February.

Two other members of the coalition have been killed while supporting Operation Inherent Resolve:

Lt. Moaz Kasasbeh, a Jordanian F-16 pilot, was captured by the Islamic State group on Dec. 24 after being shot down. He was murdered in January, when the Islamic State group burned him alive.

Sgt. Andrew Joseph Doiron, from the Canadian Special Operations Regiment, was accidentally killed by Kurdish forces on March 6.