As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKE OFF ROLL, AT ABOUT 70KTS, THE FUSELAGE DOORS MASTER WARNING. TAKEOFF WAS ABORTED & CHECKLIST WAS RUN. FOUND THE AFT CARGO DOOR HANDLE TO BE AJAR, CONSITENT WITH DOORS SYS PAGE INDICATING THE AFT CARGO DOOR OPEN. INSPECTED AFT CARGO DOOR IAW AMM 05-52-00-000-000, AND 05-0029 WITH NO DEFECTS NOTED. FUSELAGE DOOR WARNING REMAINED EXTINGUISHED. RETURNED TO SERVICE.