Law enforcement on top of prison wall during 1952 riot at Michigan State Prison in Jackson

The transcript describes a volatile situation in a prison, likened to a keg of violence ready to explode. On April 20th, 1952, tensions reached a breaking point at the Men's penitentiary in Jackson, MI, leading to a violent mutiny.

What metaphor is used to describe the potential for violence in the text?

How did the conditions in the prison contribute to the violent mutiny?