Seventeen sailors and four civilians sustained non-life threatening injuries Sunday after an explosion caused a three-alarm fire on board the USS Bonhomme Richard at the U.S. Naval Base in San Diego. The injured are being treated at an area hospital, the U.S. Navy said in a statement. San Diego Fire Chief Colin Stowell told CNN the ship could burn for days, "down to the water line." He also said the explosion took place as personnel were leaving the ship. The USS Bonhomme Richard is an amphibious assault ship, the U.S. Navy said, and was undergoing maintenance. When the fire started, there were 160 people on board. It is unclear what started the blaze.

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