As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAD INFLIGHT T1281/17FEB BOS TO DFW - AT FL320 CREW REPORTED AIRCRAFT LOST PRESSURIZATION. OXYGEN MASKS DEPLOYED. LANDED IAD WITHOUT INCIDENT. SECURED LOOSE B NUT ON LEFT PACK SENSE LINE. FERRIED TO LGA. REPLACED ALL PASSENGER AND FLIGHT ATTENDANT OXYGEN CANISTERS. SYSTEM GROUND CHECKED NORMAL OPERATION.