Trevor Fitzroy and Bantam travel back in time to 1959 and kill Professor X.
X-Men: The Animated Series
Season 4 Episode 15: Secrets, Not Long Buried
When Cyclops flies solo to a tiny, western, desert community to see an old friend, his plane is blasted out of the sky. Injured and unable to use his powers, he struggles into town, only to discover his friend is missing and the town is...