Richard D. Warner embraced life without hesitation and embodied the slogan “No Fear,” his stepfather said. “The greater the challenge, the more that Rich would throw himself into it,” Pat Donahue said. Warner, 22, of Waukesha, Wis., was killed by a bomb Dec. 13 while on a foot patrol. His Marine Reserve unit was headquartered in Milwaukee. His high school principal, Mary Schwartz, remembered Warner as an energetic student who dreamed of being a Marine and enlisted even before the terrorist attacks of Sept. 11, 2001. Warner was the nephew of O.J. Simpson’s famous houseguest, Brian “Kato” Kaelin. In an interview on a morning radio talk show in Milwaukee, Kaelin called Warner “the best kid in the world.” “The greatest guy in the world, 22, and he was taken away,” he said.