Every April, 28,000 runners descend upon the Arizona State University campus to cover the 4.2 miles of Pat's Run.
The run started in 2004 as a way to honor Pat Tillman, the football player killed by friendly fire in Afghanistan after leaving a lucrative NFL career.
Pat's Run has blossomed into much more since that inaugural run in San Jose, California, becoming a way to honor a person considered to be a hero by many and to support the foundation that bears his name.
Pat's Run has since branched out beyond the desert as people across the country joined in shadow runs in conjunction with the main event in Arizona.
This weekend, more than 3,200 people in 32 cities...