The ballistic-missile submarine USS Nebraska remained in Pearl Harbor yesterday for an investigation and any crew counseling that was needed following the death Saturday of a sailor as the submarine operated near O'ahu, the Navy said.

Lt. Cmdr. David Benham, a spokes-man for the Pacific Fleet submarine force at Pearl Harbor, said the identity of the sailor who died still was being withheld.

"They are still going through the notification process for next of kin," Benham said.

The Navy said the crew member was mortally wounded while the 560-foot-long ship was submerged. Benham said the Nebraska, which is based out of Bangor, Wash., was conducting routine operations.

No information was released about how the sailor was injured. He died en route by helicopter to The Queen's Medical Center, Benham said..

Benham said no other Nebraska crew members were injured, and that the submarine was not damaged in any way.

The Nebraska, which carries up to 24 Trident ballistic missiles, had not pulled into Pearl Harbor for a stop before the accident, the Navy said.

"The reasons for the (Pearl Harbor port visit) are twofold," Benham said. "One, the Navy intends to fully investigate this incident. So having (the sub) in port facilitates that investigation. The other piece of this is it gives the opportunity for the crew to receive grief counseling and to have access to chaplain services and those types of things here ashore that they can't get under way as readily."

Benham said he wasn't sure how long the Nebraska and its crew of about 150 will be in Pearl Harbor, but the nature of the sub's nuclear deterrent mission means the Navy doesn't advertise future operations.

The Navy's 14 Ohio-class submarines, the largest U.S. subs ever built, carry about 50 percent of the U.S. strategic nuclear warhead inventory. The subs are split between Bangor, Wash., and Kings Bay, Ga.

Four of the oldest Ohio-class ships of an original 18 were converted to carry up to 154 Tomahawk cruise missiles with conventional warheads, or up to 66 commandos.

The Nebraska, commissioned in 1993 and nicknamed "Big Red" after the University of Nebraska football team, conducted a successful test launch in May of two Trident II D5 fleet ballistic missiles as part of an ongoing evaluation.

The unarmed missiles were launched while the Nebraska was submerged in the Pacific.