US Navy officials reports two naval ships collided Wednesday morning.

The USNS Yukon and USS Essex wrecked into one another during a replenishment mission. An investigation is under way, but the understood cause of the collision is a malfunction with the steering mechanism aboard the Yukon.

According to the Navy, no one was harmed in the accident. However, damage was done to both naval vessels.

USNS Yukon is a 677.5 foot long oil ship among fifteen of the Military Sealift Command‘s Fleet Replenishment Oilers.

Last June the Yukon was taken out of commission for repairs following a collision with the USS Denver (LPD 9) off the coast of Hawaii.