As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFT P-F CONV DURING T/O CREW NOTED A LEVEL ONE AC TIE 1 OFF ALERT. FOUND A BLOCK OF THE CONCRETE BALLAST HAD BROKEN FREE OF AN LD3 CONTAINER IN POS 1 LEFT IN THE FWD LWR CARGO COMP. THE BLOCK ROLLED THRU THE FWD CARGO COMP AND PASS THRU BULKHEAD AND LODGED IN THE NR 1 EPC BAY.