right side) was opened by ground personnel. Three minutes later, the interior of the aircraft flashed over, and was destroyed by fire. Why Captain Khowyter failed to evacuate the aircraft promptly is not known. Saudi reports stated that the crew could not get the plug-type doors to open in time. It is assumed that most passengers and flight attendants were incapacitated during the landing roll, or they did not attempt to open a door on a moving aircraft. It is known that the aircraft remained pressurized during the landing roll as the cabin pressurization system was on standby, and the aircraft was found with both pressurization hatches almost completely closed. The pressurization hatches should have opened completely on touchdown to depressurize the aircraft. The crew were found still in their seats, and all the victims were found in the forward half of the fuselage. Autopsies were conducted on some of the non-Saudi nationals, including the American flight engineer. All of them perished from smoke inhalation and not burns, which indicated that they had died long before the R2 door was opened. The source of the fire in compartment C3 could not be determined. Passengers Eighty-two of the passengers boarded in Karachi while the remaining 205 passengers boarded in Riyadh. The majority of the passengers were Saudis and Pakistani religious pilgrims on their way to Mecca for a traditional Ramadan holiday. In addition to the Saudis and Pakistanis, there were 32 religious pilgrims from Iran. There were also a small number of passengers from various countries, who were heading to Jeddah for diplomatic missions. Investigation The investigation revealed the fire had started in the aft C3 cargo compartment. The fire was intense enough to burn through the cabin floor, causing passengers seated in that area of the cabin to move forward prior to the landing. Saudi officials found two butane stoves in the burned-out remains of the airliner, and a used fire extinguisher near one of them. One early theory was that the fire began in the passenger cabin when a passenger used his own butane stove to heat water for tea. The investigation found no evidence to support this theory. Policy changes After the event, the airline revised its training and emergency procedures. Lockheed also removed the insulation from above the rear cargo area, and added glass laminate structural reinforcement. The National Transportation Safety Board recommended that aircraft use halomethane