This month marks 20 years since the longest deadly prison riot in U.S. history.
The 11-day siege at the prison in Lucasville, Ohio, ended with one officer and nine inmates dead.
Some warn of the same "red flags" today that signaled the riot in 1993.
Ohio prisons director Gary Mohr authored a report on the causes of the riot and says safety and security have unquestionably improved since then.
Yet Mohr worries for the safety of prison staff, as he believes every U.S. prison director does.
He says seven corrections employees nationwide have died in the line of duty in the last two years.
After a post-riot decline, the ratio of inmates to guards in Ohio's prisons has risen over the past decade, and overcrowding remains a problem.