(CNN) -- Thirteen people aboard a skiff drowned Monday in the Gulf of Aden as the crew of the U.S. destroyer Winston S. Churchill attempted to assist the disabled vessel, a military statement said.
The skiff was found drifting in a Gulf shipping corridor on Sunday.
When U.S. Navy personnel couldn't repair its engine, the ship was towed toward the coast of Somalia and assistance was offered to the 85 people on board -- 10 Somalis and 75 Ethiopians.
"While transferring humanitarian supplies to the skiff, the passengers rushed to one side and the skiff began taking on water, quickly capsizing and sinking rapidly, leaving all 85 passengers in the water," according to the U.S. Navy.
The Navy said the destroyer crew immediately began search and rescue operations. Thirteen passengers drowned and eight were missing, the Navy said. Sixty-one passengers were rescued.
The incident is under investigation.