On 4 June, Japanese planes struck the island of Midway with little opposition, and returned to their carriers to re-arm for a second strike. Confusion on the Japanese side as to what forces they found themselves facing proved fatal, as the American air attack from "Yorktown", "Enterprise", and caught the enemy at a vulnerable moment. While torpedo planes from the three carriers successively drew off the combat air patrols, dive bombers from "Yorktown" and "Enterprise" wrought mortal damage on three of the four enemy carriers engaged.