Crews and commanders have little time to train and ships go without maintenance because of growing demands in the Pacific, a top admiral told lawmakers on Thursday.
After two deadly collisions involving Navy ships, more than a dozen current and former officers raised alarms about gaps in maintenance and training, grueling duty schedules and expanded operations.
The McCain had been on patrol in the South China Sea and was headed to Singapore when it collided with a chemical and oil tanker.
Collisions of two ships are considered rare, but the episode on Monday was the second such case involving a American naval destroyer since June.
The John S. McCain was traveling to a port in Singapore when it collided with a merchant vessel in the Strait of Malacca, the Navy said.