Callahan, 52, is survived by his wife, Stacy, daughters Alexa and Carly, and his parents Ann and Gene.
Funeral arrangements are pending and SIU will announce its plans to pay tribute to Callahan's life at a later date.
Callahan, the second winningest coach in history at SIU, complied a 442-447-1 record in 16 years at Carbondale.
