What happened
The pilot was handling all controls when he executed a normal power landing. Immediately after touchdown, throttle was applied for the takeoff attempt. As the airspeed reached approximately 50 knots, the aircraft deviated to the left and entered a violent water loop in that direction.
The force of the maneuver caused the hull to break open and partially sever at the navigator's compartment. The aircraft sank immediately following the structural failure. Despite the rapid sinking, all personnel on board were able to escape the wreckage. All individuals sustained injuries during the incident.
Findings
The accident occurred during the initial phase of the takeoff roll after a power landing. The primary mechanical event was an uncontrolled swerve to the left at low speed, which escalated into a violent loop that compromised the structural integrity of the fuselage.