The Navy says its third attempt to free a $1 billion warship that ran aground off the coast of Hawaii has failed.

Tugboats and a salvage ship tried unsuccessfully for four hours early today to pull the USS Port Royal off a rock and sand shoal. The guided missile cruiser ran aground Thursday about a half-mile south of the Honolulu airport.

Pacific Fleet spokeswoman Agnes Tauyan says the Navy is reassessing its options.

The Navy had removed fuel, water and some personnel from the 9,600-ton vessel on Saturday in an effort to lighten it.

The 15-year-old Port Royal ran aground as it was finishing the first day of sea trials following four months of routine maintenance at the Pearl Harbor Naval Shipyard.

No one was injured and no contaminants leaked.