Brian "Crush" Adams
Years active in the WWE: 1990-1997
Crush retired from wrestling after a spine surgery, though successful, forced him to stop being slammed on a mat thousands of times a year. After all paralysis is nothing to fuck with. This led Adams into a second career as a boxer with hype man Randy Savage (though pro boxers don't usually have hype men Adams reciprocated by being the head of Savage's security team while "Macho Man" attempted to become a rapper).
The boxing career tanked as Adams was too banged up after a decade and a half of wrestling so he collected on an insurance policy and planned to open a gym/wrestler training facility. He died on August 13, 2007 at the age of 43 in a death (allegedly) brought about by steroid use though, officially, the death was caused by a cocktail of drugs taken to ease an everlasting back injury.