An explosion during boat maintenance at a U.S. naval base in New Jersey injured a civilian firefighter and seven sailors, one of them seriously. One person was hospitalized with serious injuries, while the other seven sustained minor injuries, primarily smoke inhalation. Meanwhile, U.S. Navy officials said they were still trying to determine what caused the blast. The base provides ammunition and explosives for Navy vessels operating in the Atlantic. U.S. Navy has been exposed to a painful blow in May 2012 when a maintenance workers set fire to a nuclear submarine causing damages estimated at approximately half a billion dollars.