On the 12th of October, 2000, a 35-foot boat laden with explosives and two bombers on board, rammed the USS Cole, while it was refueling in Aden Harbor, Yemen. The attack occured at 11:22 a.m., local time, ripping a 32-foot by 36-foot hole in the hull and causing extensive internal damage. The blast killed 17 sailors and injured 39 others. A U.S. Navy investigation found that the ship's officers and crew failed to take a number of security measures that would have possibly prevented the attack. At the time, Yemen was rated at a "high" threat level, the fourth-highest of a five-level threat alert system. The damage from the blast took 18 months and $250 million to repair.