The Riot of '73 Oklahoma State Penitentiary - Hardcoverby Dan M. Reynolds (Author) On Friday, July 27, 1973, two records were set that day. The temperature climbed to 96 degrees, the hottest day recorded that year, and a riot at the Oklahoma State Penitentiary became the worst prison riot in U. S. history. Read the true accounts: four inmates died, and twenty three hostages were seized; several employees were injured, and some never recovered. Dan M. Reynolds retired from the Oklahoma Department of