The U.S. Navy on Wednesday relieved the Commander of the US 7th Fleet based out of Japan for “loss of confidence” in his ability to command after the service has suffered four catastrophic accidents at sea. The last two have cost multiple sailors their lives.

Admiral Scott Swift, commander of the U.S. Pacific Fleet has relieved Vice Admiral Joseph Aucoin, the three-star commander of the U.S. Seventh Fleet based in Yokosuka, Japan from his duties at the 7th Fleet’s Yokosuka base. Rear Admiral Phil Sawyer, the Pacific Fleet’s deputy commander, will immediately assume command. Sawyer had been scheduled to assume the post on Sept. 7.

The incidents include the deadly collision Monday of the destroyer USS John S. McCain with a much heavier oil tanker off Singapore, and a June 17 accident in which the destroyer USS Fitzgerald was ripped open by a larger Philippine container ship.

Seven sailors were killed in the Fitzgerald disaster, and at least some of the 10 sailors reported missing from the McCain are dead, Swift said Tuesday. The search for their remains continues inside the stricken ship as well as in a widening area of the Straits of Malacca where the collision took place.