Argo, 75, said it was one of only two times in his life he's felt scared, the other being when he stood atop a burning car at the scene of the 1995 Oklahoma City federal building bombing to capture some photographs.
In the days before cellphones and computers, Shannon filed his prison riot updates to the newsroom by telephone.
“Smoke from burned buildings still clung to the air and armed National Guardsmen — wearing gas masks — ringed the area as newsmen entered the prison,” Shannon wrote in a story that appeared in that Sunday's paper.
Camera film was flown by airplane back to Oklahoma City for processing.
Even today, Shannon still considers the riot, which sparked reforms that reshaped the Oklahoma corrections system, among the more memorable stories he's covered during his long career.
“It was life and death and destruction on a grand scale,” Shannon said.