At 6:30 a.m., 12 Devastator torpedo bombers and 28 Dauntless dive bombers from the carrier USS Yorktown attack the massed Japanese ships at Tulagi. The raid catches the Japanese and coastwatcher Martin Clemens by surprise. The American planes swoop down, and overestimate what they see, identifying a minelayer as a light cruiser, and minesweepers as transports. They hammer the targets and go home by 9:30, having sunk the destroyer Kikuzuki and three minesweepers. A second strike punches out two seaplanes and damages a patrol craft, while a third attack sinks four landing barges. The Americans lose only three planes. Despite the elated mood on Yorktown, Japanese losses are minor. The Battle of the Coral Sea has begun.