As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, NOTED NOISE FROM FWD SERVICE DOOR AREA. AIRCRAFT RETURNED TO BWI AND LANDED WITHOUT INCIDENT. INSPECTED AND FOUND A SAFETY STRAP STUCK OUTSIDE OF DOOR. RESECURED FWD SERVICE DOOR SAFETY STRAP INSPECTED DOOR AND FRAME FOR DAMAGE. NO DAMAGE NOTED, OK TO CONTINUE.