As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT JB1056 - PIT-JFK AFTER LANDING AT JFK AND AIRCRAFT AT GATE CABIN CREW COULD NOT OPEN L1 DOOR, JAMMED AND WOULD NOT DISARM. MX FOUND L1 DOOR ESCAPE SLIDE BUSTLE PIN MISSING FROM LANYARD CAUSING DOOR JAM. REMOVED AND REPLACED L1 DOOR ESCAPE SLIDE ASSY IAW AMM 25-65-01. OPS CHECK GOOD AIRCRAFT RETURNED TO SERVICE.