The HMNZS Manawanui caught fire and sank.Profile Boats/supplied/RNZA New Zealand naval ship caught fire and sank off Samoa; all those on board were rescued.The HMNZS Manawanui was conducting a hydrographic survey when it ran aground.The cause of the sinking is under investigation.A New Zealand naval ship that cost around $63 million caught fire and sank off the coast of Samoa.The vessel, named HMNZS Manawanui, ran aground on Saturday evening, according to New Zealand's Defence Force (NZDF).All 75 crew and passengers were evacuated at around 7:52 p.m.