Trekipedia

U.S.S. Essex NCC-173

The Daedalus class Starship Essex, commanded by Captain Bryce Shumar^[1], fought in the Romulan War from 2155 through 2161.^[2] In 2167, the Essex, now a Federation starship under the sector command of Admiral Uttan Narsu of Starbase 12, was reported lost. The Essex was caught in an electromagnetic storm in the atmosphere of a Class-M moon of planet Mab-Bu IV. The storm had been caused by noncorporeal criminal life forms from the Ux-Mal system who had hoped to escape aboard the Essex. The ship was destroyed and all 229 crew members killed. In 2368, the U.S.S. Enterprise NCC-1701-D encountered beings who claimed to be members of the Essex crew, marooned and rendered noncorporeal since 2167. These beings were, in fact, the Ux-Mal criminals, who sought to escape by commandeering the Enterprise.^[1]