Guided-missile destroyer USS John S. McCain (DDG 56) moored pier side at Changi Naval Base, Republic of Singapore following a collision with the merchant vessel Alnic MC while underway east of the Straits of Malacca and Singapore on Aug. 21, 2017. Significant damage to the hull resulted in flooding to nearby compartments, including crew berthing, machinery, and communications rooms. (Grady T. Fontana/Navy)
An Army carry team moves a transfer case containing the remains of Staff Sgt. Aaron R. Butler at Dover Air Force Base, Del., Aug. 18, 2017. According to the Department of Defense, Butler, 27, Monticello, Utah, died Aug. 16 in Nangarhar province, Afghanistan, of injuries sustained from an improvised explosive device while conducting combat operations. (Steve Ruark/AP)
Honolulu ocean safety lifeguards on jet skis hand over materials to military personnel stationed at a command center at a boat harbor Aug. 16, 2017, in Haleiwa, Hawaii. An Army helicopter with five on board crashed several miles off Oahu's North Shore late Tuesday. (Marco Garcia/AP)
A U.S. Air Force U-2 prepares to land at the Osan Air Base in Pyeongtaek, South Korea, Aug. 21, 2017. U.S. and South Korean troops kicked off their annual drills Monday that come after U.S. President Donald Trump and North Korea exchanged warlike rhetoric in the wake of the North's two intercontinental ballistic missile tests last month. (Lee Sang-hack/Yonhap via AP)
U.S. soldiers with Bravo Battery, 3rd Battalion, 29th Field Artillery Regiment, 3rd Armored Brigade Combat Team, 4th Infantry Division, conduct a Fire Coordination Exercise with M109A6 Paladins at the 7th Army Training Command's Grafenwoehr Training Area, Germany, Aug. 21, 2017. (Gertrud Zach/Army)
Erin Elizabeth Rehm receives an American flag from Navy Vice Adm. Jan Tighe during a graveside service for her husband, Chief Petty Officer Gary Leo Rehm Jr., at Arlington National Cemetery in Arlington, Va., Aug. 16, 2017. Rehm died when the USS Fitzgerald was involved in a collision with a Philippine-flagged merchant vessel off the coast of Japan on June 17. (Elizabeth Fraser/Army)
Marine Corps Lance Cpl. Dakota Yates waits in a light armored vehicle for a convoy to depart from a command post in Hokkaido, Japan, Aug. 16, 2017, during exercise Northern Viper 17. (Sgt. Ally Beiswanger/Marine Corps)
A military working dog team sweeps the exterior of the National Air and Space Intelligence Center during an active shooter exercise at Wright-Patterson Air Force Base, Ohio, Aug. 2, 2017. (Wesley Farnsworth/Air Force)
Marine Corps recruits crawl through tunnels on a bayonet assault course at Marine Corps Recruit Depot San Diego, Aug. 8, 2017. (Cpl. Angelica Annastas/Marine Corps)
Republic of Singapore Air Force personnel conduct a search-and-rescue operation for missing U.S. sailors over waters east of Singapore, Aug. 21, 2017. The U.S. Navy ordered a broad investigation Monday into the performance and readiness of the Pacific-based 7th Fleet after an early morning collision between the USS John S. McCain and an oil tanker in Southeast Asian waters which left a number of U.S. sailors missing and others injured. (Ministry of Defence Singapore via AP)