Twenty people are missing in the North Pacific, after a supply ship sank about 130 kilometres from the Marshall Islands capital Majuro.
The Marshall Islands Shipping Corporation says the 27-metre vessel, carrying heavy equipment and construction materials to workers building a school on Likiep atoll, sank early on Friday morning.
A US Coastguard plane has been sent from Hawaii to search for survivors.
The corporation says the crew gave good co-ordinates before the boat sank, and it was carrying two life rafts and enough life jackets for everyone.