The Mutants - Earth -52 - Batman: The Red Death

A Gotham street-gang known for their sadism, cruelty and violence, The Mutants, overran the streets, clashing with the G.C.P.D during the final days of their world. With law enforcement ill-equipped to deal with the sharp increase in crime, authorities prepared to blow the bridges, isolating the city and turning it into its own No-Mans Land. 

Gotham - Earth -52 - Batman: The Red Death

As the red skies appeared over the city, Gotham began to tear itself apart in fear, chaos and disorder. As hard as they tried, the G.C.P.D was unable to stem the increased hostile and criminal activity, leading to countless fatalities with no signs of stopping. 

Calling for an evacuation, authorities planned to destroy the bridges in and out of the city, trapping the rioters, looters, gangs and costumed criminals on the island. There they would fend for themselves in their own little No-Man's Land. 

However before the order could be carried out, The Red Death appeared and began killing every known costumed criminal he could find. Speeding through the city, he slaughtered, Scarecrow, Penguin, Man-Bat and Riddler, hoping his extreme methods of justice could bring order to Gotham. 

Nevertheless, Wayne could not stop the destruction of his world, killing everyone, save for himself, who was rescued by The Batman Who Laughs and his Dark Knights.