Report of Investigation: Fireball Sighted Near Flagstaff, Arizona on 18 April 1949

This document is a comprehensive report of investigation conducted by the Office of Special Investigations (OSI) regarding a series of fireball sightings reported in the vicinity of Flagstaff, Arizona, on 18 April 1949. The investigation was initiated following reports in the Phoenix Gazette and Arizona Daily Sun, which described a large, brilliant green fireball traveling in a northwesterly direction. The report details interviews with several witnesses, most notably a bus driver for the Continental Bus System and a local Lutheran pastor who was also an amateur astronomer. Both witnesses observed the object at approximately 0145 hours. The pastor, who was sitting in the rear of a bus, described the object as having a greenish-blue color with a bluish tail, appearing to be the size of a 100-watt light bulb at 25 feet. He noted that the object traveled in a straight line and disappeared behind an obstacle. The bus driver, who was driving on Highway 66, provided a similar account, noting the object's brilliance and its movement at an altitude of 20 to 30 degrees above the horizon. The investigation included a review of weather reports from the U.S. Weather Bureau in Flagstaff to determine if atmospheric conditions could explain the sightings. The report concludes that the phenomenon was a large fireball or meteorite. The document includes various administrative records, including correspondence between the 17th District OSI and the Air Materiel Command at Wright-Patterson Air Force Base, as well as copies of the original newspaper articles and a sectional aeronautical chart used to pinpoint the location of the sightings. The investigation was ultimately closed with the classification of the event as an 'Astro (FIREBALL)'.