As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, IN THE CEILING BY THE L1 ENTRY DOOR, THE DESCENT DEVICE CONTAINER'S DOOR OPENED AND ONE DESCENT DEVICE UNWOUND TO THE FLOOR. WHILE THE AIRPLANE WAS REMOVED FROM SERVICE (GROUNDED), THE DESCENT DEVICE WAS REPLACED WITH A SERVICEABLE DESCENT DEVICE AND THE CONTAINER'S DOOR WAS CLOSED. THE CAUSE FOR THE DESCENT DEVICE CONTAINER'S DOOR OPENING AND THE DESCENT DEVICE DROPPING OUT IS UNKNOWN.