United Airlines Flight 624  United Airlines Flight 624, a Douglas DC-6 airliner, registration NC37506, was a scheduled passenger flight that originated in San Diego, California with stops in Los Angeles and Chicago en route to LaGuardia Airport in New York City. The four-engine propeller-driven airplane crashed at 1:41 p.m. Eastern Daylight Time on June 17, 1948 outside of Aristes, Pennsylvania, killing all 4 crew members and 39 passengers on board. Flight 624 from San Diego had just completed a routine initial descent as part of its approach into the New York area, when the forward cargo hold fire indicator light illuminated, leading the flight crew to believe there was a fire in that cargo hold. Although this later turned out to be a false alarm, the crew decided to discharge bottles into the forward cargo hold, to try to extinguish the possible fire. While proper operating procedure called for opening the cabin pressure relief valves prior to discharging the bottles, to allow for venting of the gas buildup in the cabin and cockpit, there was no evidence the crew opened the relief valves. Consequently, the released gas seeped back into the cockpit from the front cargo hold and apparently partially incapacitated the flight crew. The crew then put the aircraft into an emergency descent, and as it descended lower it hit a high voltage power line, bursting into flames, then smashing through the trees of a wooded hillside. Among the passengers were Broadway theatre impresario Earl Carroll and his girlfriend, actress Beryl Wallace, plus Henry L. Jackson, men's fashion editor of "Collier's Weekly" magazine and co-founder of "Esquire Magazine". An interesting item discovered in the wreckage was a script of Garry Moore's "Take It or Leave It" show broadcast at the time each Sunday night over NBC, but an NBC spokesman in New York said he was "certain" Moore was not on the plane. The Civil Aeronautics Board investigated the crash and published a narrative describing the following sequence of events in its final report:The airplane, named "Mainliner Utah", arrived in Chicago at 09:52 en route from Los Angeles to New York. After a 52-minute turnaround, the DC-6 departed for New York. The airplane climbed en route to its planned altitude of 17,000 feet. At 12:23, and at 12:27 the crew made a routine acknowledgment of a clearance to descend en route to an altitude between 13,000 and 11,000 feet.