USA Today reports:
River, who stood 6-foot-8 and weighed about 575 pounds, gained a measure of fame in the past year as spokesman for the Heart Attack Grill, a Chandler, Ariz., restaurant that specializes in thick hamburgers and fries. He died on Tuesday at the age of 29.
The cause of death is currently unknown, but friends are speculating that it was the result of his contracting pneumonia after a bout with the flu.
"Cynical people might think this (River's death) is funny," Basso [founder of the Heart Attack Grill] said. "But people who knew him are crying their eyes out. There is a lot of mourning going on around here. You couldn't have found a better person...."