, there have been seven recorded deaths resulting from sanctioned Mixed Martial Arts contests and nine from unregulated bouts, none however in the largest MMA promotion Ultimate Fighting Championship. A 2006 study suggests that the risk of injury in general in MMA is comparable to that in professional boxing. For professional boxing matches, the Manuel Velazquez Boxing Fatality Collection lists 923 deaths during the 118-year period of 1890–2007. List of fatalities In sanctioned fights Sam Vasquez 35-year-old Sam Vasquez collapsed after taking a punch to the chin during a fight on October 20, 2007. After losing consciousness and experiencing what appeared to be a seizure, he was taken to Saint Joseph Medical Center Critical Care Unit. He was diagnosed with a subdural hemorrhage for which a section of the skull bone was removed to allow the brain to swell without compressing it. Additional swelling led to the placement of a tube to allow cerebral spinal fluid to be drained out of the cavities in the brain to make room for more swelling as well as to allow the monitoring of pressure in the brain. He slipped into a coma for 48 hours until his death on November 30. Vasquez's death was officially ruled as a death due to complications of blunt trauma of the head with a subdural hemorrhage. Vasquez was the first fighter to die from injuries sustained in sanctioned mixed martial arts competition in North America. Michael K Kirkham 30-year-old Michael Kirkham competed at Dash Entertainment/King MMA "Confrontation at the Convocation Center" at the University of South Carolina Aiken campus in Aiken, South Carolina, on June 26, 2010. His opponent Carlos Iraburo had Kirkham on the canvas seconds into his pro debut; Iraburo then landed a few strikes to the head of his grounded opponent leading to a referee stoppage 41 seconds into the match. Kirkham soon lost consciousness and never recovered. He was pronounced dead two days after the fight. An autopsy report listed the cause of death as "subarachnoid hemorrhage of the brain". Kirkham had been TKO'd in his final amateur bout on April 24, 2010, leading Dr. Joe Estwanik, the former medical advisor to the North Carolina Boxing Authority to speculate: "This could have been second-impact syndrome." Typically, to avoid such, combat sporting authorities have the right to suspend a contestant longer than the normal 45 days (with 30 days of no contact) for a