What happened
The aircraft was operating in cruise flight when the exterior skin failed due to fatigue. This structural failure resulted in an immediate loss of cabin pressure. In response to the depressurization, the passenger oxygen masks deployed automatically.
The flight crew immediately donned their own oxygen masks and declared an emergency to air traffic control (ATC). The crew initiated a descent to 10,000 feet to ensure adequate breathing conditions. The aircraft was diverted to a suitable airport for landing. The landing occurred without further incident or damage.
The investigation
The investigation identified that the exterior skin had failed due to fatigue while the aircraft was in cruise flight. This failure mode directly caused the loss of cabin pressure.