SEATTLE — A Navy investigation has concluded that a sailor who died on the nuclear missile-carrying submarine USS Nebraska in September in waters off Hawai'i ignored posted warnings.

The Kitsap Sun reports that Michael A. Gentile died after being pinned by the ram that operates the submarine's rudder. At the time of Gentile's death, the Bangor, Wash.-based submarine was conducting routine operations off the coast of Hawai'i.

The Navy released its findings on Wednesday.

Submarine Group Trident spokesman Lt. Kyle Raines said the 21-year-old sailor was standing watch when the accident occurred. Gentile, originally from Maine, was flown to a nearby hospital after the accident but died en route.

Raines said none of the submarine's officers will lose their jobs, but were reprimanded through administrative action.