Originally published on ProWrestlingSheet.

Wrestling's top names -- past and present -- are reacting to the news of Jim "The Anvil" Neidhart passing away at just 63 years old.

At this point, it's unclear what took the life of the former tag team champion and father of current WWE star Natalya -- and his passing seems to have caught many by surprise.

"Stunned and saddened," wrote tag team partner Bret "The Hitman" Hart. "I just don’t have the words right now."

"Saddened to hear Jim Neidhart has passed away," tweeted WWE Hall of Famer Sgt. Slaughter. "My prayers are with his family.  Guess God needed an "Anvil" angel."

"Sad to hear about the passing of Jim Neidhart," wrote Eric Bischoff. "Condolences to his family, friends and fans. Jim was an important part of the landscape during one of the most important periods in the industry. RIP Jim."

Read below for more of the reactions pouring in on social media.