Calling it "a really sad day," Arizona Wildcats coach Rich Rodriguez is mourning the loss of his longtime assistant and eventual successor at West Virginia. 

Bill Stewart died today of an apparent heart attack. He was 59. Stewart went 28-12 in three seasons as the Mountaineers' head coach before being replaced by Oklahoma State offensive coordinator Dana Holgorsen. Stewart served on Rodriguez's staff from 2001-07, and was named head coach when Rodriguez left to the University of Michigan. 

Said Rodriguez: "We spent seven great years together at West Virginia. He was an outstanding person, coach and friend to everybody on the staff. Our thoughts and prayers are with his wife, Karen, his son,  Blaine and his many friends and family.”

The sports editor of the Arizona Daily Star.