On 12 August the (US) National Transportation Safety Board announced that the 21 August 2017 collision between the USS John S McCain and the tanker Alnic MC was caused by insufficient training, inadequate bridge operating procedures and a lack of operational oversight.

Ten sailors aboard John S McCain died in the accident and 48 were injured when the ships collided in the Middle Channel passage of the Singapore Strait Traffic Separation Scheme. There were no injuries to the crew of Alnic MC. Property damage resulting from the collision exceeded $1.2 million. There was no report of pollution associated with the accident.