Pan Am Flight 214 was a scheduled flight of Pan American World Airways from Isla Verde International Airport in San Juan, Puerto Rico, to Friendship Airport in Baltimore and Philadelphia International Airport. On December 8, 1963, the Boeing 707-121 serving the flight crashed near Elkton, Maryland, while flying from Baltimore to Philadelphia, after being hit by lightning. All 81 occupants of the plane were killed. The crash was Pan Am's first fatal accident with the 707, which it had introduced to its fleet five years earlier. An investigation by the Civil Aeronautics Board concluded that the cause of the crash was a lightning strike that had ignited fuel vapors in one of the aircraft's fuel tanks, causing an explosion that destroyed one of the wings. The exact manner of ignition was never determined, but the investigation yielded information about how lightning can damage aircraft, leading to new safety regulations. The crash also spawned research into the safety of various types of aviation fuel and into methods of reducing dangerous fuel-tank vapors. Accident Pan Am Flight 214 was a regularly scheduled flight from Isla Verde International Airport in San Juan, Puerto Rico, to Philadelphia International Airport, with a scheduled stopover at Baltimore's Friendship Airport. It operated three times a week as the counterpart to Flight 213, which flew from Philadelphia to San Juan via Baltimore earlier the same day. Flight 214 left San Juan at 4:10pm. Eastern time with 140 passengers and eight crew members, and arrived in Baltimore at 7:10pm. The crew did not report any maintenance issues or problems during the flight. After 67 passengers disembarked in Baltimore, the aircraft departed at 8:24pm with its remaining 73 passengers for the final leg to Philadelphia International Airport. As the flight approached Philadelphia, the pilots made radio contact with air traffic control near Philadelphia at 8:42pm. The controller informed the pilots that the airport was experiencing a line of thunderstorms in the vicinity, accompanied by strong winds and turbulence. The controller asked whether the pilots wanted to proceed directly to the airport or to enter a holding pattern to wait for the storm to pass. The crew elected to remain at in a holding pattern with five other aircraft. The controller told the pilots that the delay would last about 30minutes. Heavy rain was falling in the holding area, with frequent lightning and gusts of wind up to . At 8:58pm,