A VP-44 PBY sighted Tanaka's transport group about 500 miles from Midway on June 3, and Midway-based bombers attacked it that afternoon. The level bombers claimed hits but missed; a PBY torpedo struck a ship early on June 4. In this reading, the June 3 sighting and attack mark the true opening of the battle because they proved the Americans knew an operation was approaching. Japan still neither concentrated for mutual defence nor revised its dispersed timetable. Operational surprise had failed before Nagumo launched against the island.
Notable Point · 1:44:26-1:48:13
The June 3 warning that Japan left unanswered
A PBY sighting and bomber attack on June 3 warned Japan that its occupation force had been found, yet commanders continued with their dispersed plan.