MMA Fighting, citing its own sources in law enforcement, informs that the fighter passed away on Thursday. The official cause of Bonnar's death has not been established, but the UFC said in a statement that it was due to heart problems.
“Stefan Bonnar was one of the most important fighters ever to fight in the octagon. His fight with Forrest Griffin changed the sport forever. He will never be forgotten. The fans loved him, and he always tried his best for them. We will miss him,” said UFC head Dana White.
Bonnard spent 24 fights in his professional career, scoring 15 victories and suffering nine defeats. The American ended his career at the end of 2014 after losing a split decision to Tito Ortiz.