As the 1990s dawned, Stronghold suffered the worst disaster in its history. After a freak thunderstorm knocked out a portion of the prison’s power grid, the prison descended into chaos. A group of inmates led by Blackstar of the Ultimates made a break for the surface, freeing as many villains as they could along the way. By daybreak, more than 40 hardened supervillains were on the loose. This was known as the Great Stronghold Breakout.