What happened
The crew was returning to Casco Cove Guard Station on Attu Island following an uneventful mission. During the approach phase, the pilot assessed the sea conditions and determined that the water was too rough for a safe landing at the original destination. Consequently, the decision was made to divert to Massacre Bay, where conditions appeared more favorable.
Upon attempting to land at the new location, the seaplane was struck by a wave. This impact caused the aircraft to plunge into the sea and subsequently sink. All occupants managed to evacuate the cabin before the aircraft was lost. The seaplane was carrying a cargo of 1,200 gallons of fuel and two bombs at the time of the accident.
Findings
The official investigation concluded that the accident occurred because the aircraft was hit by a wave while landing on rough sea.