adam cook

Reigning "American Idol" champ David Cook stunned the crowd at today's Race for Hope 5K in downtown D.C. by announcing his brother died the night before of a brain tumor -- the cause that got him involved in the annual fundraiser.Adam Cook, 36, a lawyer with a wife and children, had battled the tumor for more than a decade before dying in Terre Haute, Ind.

David Cook joined 9,000 other runners this morning -- finishing the 3.1 mile course in 28 minutes, he later said -- before taking the stage. This year's race, the 12th annual, raised $2 million for brain cancer research.

"I couldn't imagine being anywhere else right now," Cook said, getting briefly choked up and wiping away tears. "I've lost one but I've gained 9,000 ..... I will be here every year that they will have me