Kimbo Slice, a professional mixed martial arts fighter who gained notoriety through backyard fights posted to YouTube, died Monday (June 6) at the age of 42, Bellator MMA announced. ESPN reported earlier this morning that a cause of death was still unknown, though SB Nation is citing the Orlando Sentinel's report that a heart failure was to blame.

"We are all shocked and saddened by the devastating and untimely loss of Kimbo Slice, a beloved member of the Bellator family," Bellator president Scott Coker said in a statement. He additionally called Slice "a charismatic, larger-than-life personality that transcended the sport."

Many in hip-hop took to Twitter following the news of Slice's passing to remember the fallen fighter, particularly his 21st century come-up. Beatking wrote, "Kimbo Slice was the first fighter to come up like a underground rapper. He put his fights on YouTube and built a buzz!"

The fighter also made his way into plenty of hip-hop lyrics including bars from Young Thug and Rick Ross, with the latter rapping "Kimbo Slice on the pad when I write" on 2009's "Mafia Music."

Included up above is a gallery of reactions to the news of Slice's untimely passing, with tweets from the likes of Big Boi, Bodega BAMZ and more, while ESPN and SB Nation feature additional quotes and details on the loss. At six-foot-two, 225 pounds, Kimbo fought as a heavyweight with a 5-2 professional record that included four TKOs. He last fought on Feb. 19 and was scheduled to headline Bellator 158 on July 16 in London.