Roswell.

Roswell refers to the July 1947 recovery of debris on a ranch near Roswell, New Mexico, after which the Roswell Army Air Field briefly announced it had recovered a 'flying disc' before retracting it as a weather balloon. The USAF later identified it as a classified Project Mogul high-altitude balloon train meant to detect Soviet nuclear tests; the 'alien bodies' element grew from 1978 onward via Stanton Friedman and witnesses like Jesse Marcel. It matters as the founding event of modern crash-retrieval mythology, the template every later 'crashed-saucer' claim imitates.