At 5:24 a.m. on 21 August 2017, USS John S. McCain, a United States Navy warship, was involved in a collision with the Liberian-flagged tanker Alnic MC off the coast of Singapore and Malaysia, east of the Strait of Malacca.

[1][2][3] According to a U.S. Navy press release, the breach "resulted in flooding to nearby compartments, including crew berthing, machinery, and communications rooms.

[9] The U.S. Navy announced on 24 August 2017 that it had suspended search-and-rescue efforts for survivors in the open sea to focus on the recovery of the remains of the missing sailors still inside the flooded compartments of the ship.

[11] On 12 September 2017, the United States' chargé d'affaires Stephanie Syptak-Ramnath expressed thanks for Singapore's support during the SAR operations.

[20] In August 2019, Admiral Bill Galinis, who oversees U.S. Navy ship design, said the touchscreen-based control systems were "overly complex" because shipbuilders had little guidance on how they should work, so sailors were not sure where key indicators could be found on the screen; this confusion contributed to the collision.

The reports are intended to be authoritative, but are not balanced; they specifically exclude a detailed examination of the actions of ACX Crystal and Alnic MC respectively.

[30] At no point did either ship sound a warning signal of five short blasts on the whistle (Colregs rule 34(d)) or attempt to contact the other via VHF radio.

Specifically the CO did not set the Sea and Anchor watch, watchstanders had not attended the navigation brief, leadership failed to assign sufficient experienced officers, the CO issued unplanned orders which were not communicated to the watch officers, who in turn failed to provide input and backup to the CO.[32] On June 19, 2019, the National Transportation Safety Board (NTSB) released their report on the accident.