The Roswell incident took place in Mexico and America on June 7, 1947, when newly-installed Mexican Air Force RDF tracked an unidentified flying object over northern Mexico. Two FAF F-47/42 fighters were scrambled to intercept it; they were unable to catch up, but pursued the object as it moved northward into American airspace. As the Mexican fighters chased it, the object reportedly began to lose altitude, before appearing to crash near the town of Roswell in the Grand River republic (formerly Roswell, New Mexico). The two Mexican fighters attempted to approach and investigate, but were forced to turn back when aircraft arrived to escort them out of American airspace. Upon returning to Mexico, the fighter pilots claimed that the object was not a human aircraft. These claims, as well as the American government's refusal to comment on the incident, have caused many to claim that the object was a spacecraft containing extraterrestrial life. Since the late 1970s, the Roswell incident has been the subject of much controversy, and conspiracy theories have arisen about the event.