SAN DIEGO — The Navy says the fire aboard the USS Bonhomme Richard reportedly began in the lower vehicle storage area and led to an internal explosion at 8:30 a.m on Sunday. Firefighters are still battling the flames as the ship remains at Naval Base San Diego. The cause of the fire is unknown.<br /><br />Speaking at a news event, Rear Admiral Philip Sobeck says the fire damaged the front deck and superstructure, and collapsed the front mast. The ship is without munitions but has a million gallons of fuel two decks below the flames. The Pacific Fleet says 59 sailors and civilians are non-critically injured.<br /><br />Defense News reports the warship was about to complete upgrades for operating F-35 jets. According to the Navy, the ship's Halon fire suppression system had been disengaged because it was undergoing maintenance.<br /><br />According to Sobeck, Helicopter Sea Combat Squadron Three's Seahawks dropped 415 buckets of water on the vessel, and 400 sailors are fighting to save the ship. In a separate statement, San Diego Fire Department Chief Colin Stowell, whose firefighters are helping the effort, told CNN that the ship could burn "down to the waterlines."