Awwal 19, 1432 H/Feb 22, 2011, SPA --Pirates killed four Americans Tuesday aboard a captured yacht off the coast of Somalia, the US military said. The US Navy had been trailing the yacht, the S/V Quest, since Friday, when it was hijacked by the pirates, who took the four Americans hostage. The Navy stormed the vessel after detecting gunfire and discovered the Americans had been shot by their captors, dpa quoted US Central Command, based in Tampa, Florida, as saying. Two pirates died during the confrontation and 13 were captured, and the bodies of two other pirates already dead were found aboard the yacht, said Central Command, which oversees US military operations in the region. The Navy provided immediate care to the hostages, but was unable to save their lives. News reports said the pirates were Somali, but Central Command said it had yet to confirm their nationality, a spokeswoman said. The sailors aboard the S/V Quest had been participating in the Blue Water Rally off the coast of India before diverting on another route February 15, a rally official said over the weekend. The official identified the four Americans as Scott and Jean Adam, and Phyllis Macay and Bob Riggle.