Roswell crash

The Roswell crash was an event in 1947 where an alien spaceship crashed in Roswell, New Mexico.

Overview
In an event that the Doctor described as an "alien fender-bender" (NSA: Peacemaker), a Nedenah ship was damaged and crashed to Earth. As "the Greys", the humanoid aliens later made infamous by UFO lore. (PDA: The Devil Goblins from Neptune).

Three survivors were taken by the American government to a secret base to be studied. The Americans who discovered it were able to strip it for parts, and were capable of creating many new devices derived from the technology. Broadband internet was derived from a mileometer found in the crash. (DW: Dalek) They were also able to reverse engineer and recreate the schematics for the ship. (SJA: Prisoner of the Judoon)

Another spaceship also crashed there in 1947 piloted by Seruba Velak. She was being chased by the Viperox, this led to the Viperox almost gaining control of the Earth 11 years later. (DW: Dreamland)

Sarah Jane Smith seemed to think of it only as a minor event in the history of human-alien contact. (SJA: Enemy of the Bane)