Temple, CaliforniaApril 1957

On April 9, 1957, a sonic boom woke residents of the San Gabriel Valley in Southern California. Later that morning, ten-year-old Pat Murphy discovered a strange cone-shaped hole in his family's backyard in nearby Temple, California. The hole was about 30 inches wide and two feet deep. Pat's father, Oscar Murphy, called the Temple City sheriff's office to report it.

Sheriff's deputies investigated and decided the matter was beyond their authority. They contacted the Army's Explosive Ordnance Disposal squad at Fort MacArthur. Captain Robert Jackson and his team arrived early the following day, convinced that "something from the air had entered the ground." They believed the object was roughly six to eight inches in diameter, and it could be anything from a meteorite to a piece of falling aircraft to an unexploded bomb or missile. For safety, they decided to dig.

Army crews worked carefully, digging down to a depth of about 15 to 20 feet. Two Air Force intelligence officers showed up on the scene, though they had little to say publicly. One officer, Lieutenant Charles Hoskins, did manage to concede that "there's definitely a hole in the ground." The ground was carefully probed with mine detectors and shovels. By the time the search ended, Army crews and deputies had filled the Murphy family's yard with equipment, filled-in excavated soil, and curiosity seekers. The digging turned up nothing of interest except an old baby carriage, a tin can, some concrete debris, and a piece of garden hose, all clearly unrelated to the impact.

Captain Jackson later stated that he had checked with nearby Air Force bases and found no reports of missing missiles, bombs, or equipment. The hole's origin remained unknown. The file notes that the connection between the sonic boom and the mysterious hole was never determined, though a meteorite remained a possibility despite no meteorite being found. The full case file is reproduced below as held by the National Archives, containing 13 pages.