At the Battle of Hogwarts, this character was killed:
Then Neville nearly walked into him. He was only half of a pair that was carrying a body in from the grounds. Harry glanced down and felt another dull blow to his stomach: Colin Creevey, though underage, must have sneaked back just as Malfoy, Crabbe, and Goyle had done. He was tiny in death.
But we don't know where or when he died, or how. Is there any evidence as to who killed him?