As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AS THROTTLES WERE ADVANCED FOR TAKEOFF, THE NR 2 ENGINE EXPERIENCED A CONTAINED FAILURE. THE TAKEOFF WAS ABORTED AT 20 KNOTS AND THE CREW FOLLOWED ECHM PROCEDURES WITH ONE ENGINE FIRE BOTTLE BEING DISCHARGED. EMERGENCY EQUIPMENT AND NWA MAINTENANCE WERE CALLED. MAINTENANCE FOUND METAL IN THE TAILPIPE AND THE AIRCRAFT RETURNED TO THE GATE. REPLACED THE NR 2 ENGINE.