Why did the Battle of Midway happen?

Following the Doolittle Raid on Tokyo, the Japanese felt it needed to destroy the US Pacific Fleet to prevent further US raids. They chose to attack Midway to lure the American carriers into the open, in the hopes of destroying it. Instead, due to the American code breakers decoding the Japanese naval traffic, the Americans knew of the plan, and planned an ambush of their own. In the event, the Americans sank all four Japanese carriers with the loss of only one of their own, turning the tide of victory on the Pacific.