As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IR - ON DEPARTURE, LOUD BANG HEARD FOLLOWED BY BAD SMELL IN CABIN. PACK OFF LIGHT FOLLOWED BY NO AIR PRESSURE IN LT MANIFOLD. RETURNED FRA. FOUND ONE LT WING L/E SUPPLY DUCT AND ONE C/O SUPPLY DUCT. REPLACED BLOWN DUCTS, LEAK AND OPS CHECK NORMAL.