SHARECOMMENTMORE

Thanks for the outpouring of condolences, but he's already dead.

A Twitter mixup Tuesday led to an explosion of posts celebrating the life of lengendary astronaut Neil Armstrong. ABC News appeared to post a new obit for Armstrong online, but it actually was an old story with a new video.

Regardless of what happened, the new time stamp on the Armstrong obituary led to the hashtag #RIPNEILARMSTRONG, which became one of the most-used on Twitter yesterday.

Death mixups and hoaxes aren't infrequent on social media: Celebs like Paul McCartney, Celine Dion, Chris Brown and Justin Bieber have all been incorrectly killed off on Twitter and Facebook.