Former WWE wrestler Robert Horne, also known as Sir Mo, died Sunday night at a Texas hospital at the age of 58, according to a report from TMZ.

The outlet stated that Horne had been dealing with kidney issues for years, and his health was on the decline in the months leading to his death, which was confirmed by his brother, Gerald. Horne had been dealing with pneumonia as well as a blood infection.

Horne was best known for being one half of Men on a Mission, his tag team with Mabel (real name Nelson Frazier, AKA Viscera). They first started working together outside of WWE before being brought into the promotion in 1993. The company soon paired them up with a manager known as Oscar, but he soon left WWE, and Men on a Mission continued as a duo. The team won the tag titles together in March 1994, but their reign lasted just two days. 

As their careers continued, Mabel began to take off as a singles wrestler, with Sir Mo often acting as his manager before eventually moving to the independent scene. Mabel later died in 2014 at 43 years old.

Following Horne’s death, Mark Henry took to X to share a post in tribute of the late wrestler, with Henry writing about crossing paths with Horne several times over the years. Similarly, WWE onscreen authority figure Adam Pearce made a post about Horne’s friendship and wished the performer’s family well. Former AEW guest wrestler RYZIN posted a longer statement about Horne ahead of the wrestler’s death, with RYZIN stating that he’d worked closely with the former WWE tag champ and commending him for his kindness and generosity.

Just last year, Horne was inducted into the Memphis Wrestling Hall of Fame, as he and Mabel had prominent runs in the city’s USWA promotion both before and after their time in WWE.

The Wrestling Inc. staff would like to extend its condolences to the family and friends of Robert Horne.