The United States Navy on Wednesday said that the collision of its guided missile destroyer with a merchant ship near Singapore in August, in which 10 sailors were killed, was preventable. The commander of USS John McCain and his deputy have been relieved from their duties, Reuters reported.

“The commanding officer exercised poor judgement, and the executive officer exercised poor leadership of the ship’s training programme,” said the USS Seventh Fleet, which has its headquarters in Japan. Commander A Sanchez and his executive officer, Commander J Sanchez, have been reassigned to other duties in Japan.

The USS John McCain had collided with oil tanker Alnic MC as it was passing the entrance of the Strait of Malacca. The ship, which was carrying the Aegis missile defence system capable of countering a North Korean missile attack, was on its way to Singapore’s Changi naval base.

After a series of similar collisions, the US Navy’s command in the Pacific saw a number of changes. The Navy removed Seventh Fleet chief Vice Admiral Joseph Aucoin from the post saying it was no longer confident in his ability to command. Also, the admiral who headed the US Navy in the Pacific announced his plans to retire in September after he was not promoted to head all US military forces in the region.

In June, seven sailors died after the USS McCain’s sister ship, the Fitzgerald, nearly sank off the coast of Japan after colliding with a Philippine container ship.