A mixed martial arts fighter has died in a hospice about six weeks after he was injured in a sanctioned bout, a rare fatality for a combat sport that is growing in popularity. Sam Vasquez, 35, of Houston, was injured at the Toyota Center on Oct. 20 and died Friday. The Harris County Medical Examiner's Office confirmed Vasquez's death, but spokeswoman Stacey Mitchell said it could be several days before the official cause is determined. Vasquez was hospitalized after he was knocked out by Vince Libardi of San Antonio in the third round of a fight at the Renegades Extreme Fighting show. He lost consciousness and suffered a seizure. A fan Web site said Vasquez was the first such fighter to die from an injury incurred or aggravated while competing in a regulated bout, though no official statistics were available.