The Navy’s 7th Fleet said the USS John S. McCain collided with the merchant vessel Alnic MC while the destroyer was making its way to a port visit in Singapore. The collision was reported at 5:24 am local time, east of the Malacca Strait, one of the world’s most congested shipping routes.

The Navy reported significant hull damage to the McCain, saying there was flooding in berthing compartments as well as machinery and communication rooms.