A clear day over the Grand Canyon and two commercial airliners run right into each other. 128 perish, no survivors. 

The original entry lives at: https://en.wikipedia.org/wiki/1956_Grand_Canyon_mid-air_collision

From ChatGPT: The 1956 Grand Canyon mid-air collision was a major aviation accident that occurred on June 30, 1956. It involved two commercial airplanes, a United Airlines Douglas DC-7 and a TWA Lockheed Super Constellation, which collided in mid-air over the Grand Canyon in Arizona, United States. All 128 passengers and crew members on board both planes were killed in the crash, making it one of the deadliest aviation accidents in American history at the time.

The two planes were flying at the same altitude of 21,000 feet and on intersecting flight paths in the airspace over the Grand Canyon, which was then uncontrolled airspace without radar coverage. The TWA flight was en route to Kansas City, Missouri, from Los Angeles, while the United flight was traveling from New York City to Los Angeles with a scheduled stopover in Chicago.

Following the collision, debris from the two planes rained down over a large area of the Grand Canyon, making it difficult for rescue teams to access the crash site. The accident was a significant wake-up call for the aviation industry and the U.S. government, which had previously resisted efforts to implement modern air traffic control systems and radar coverage.

The disaster led to significant changes in aviation regulation, including the establishment of the Federal Aviation Administration (FAA) and the implementation of modern air traffic control systems, which included the use of radar to monitor airspace. The incident also led to improvements in aircraft collision avoidance systems and cockpit communication protocols to prevent future accidents.

The 1956 Grand Canyon mid-air collision remains an important event in aviation history and a reminder of the importance of prioritizing safety in air travel.