In the comic Crisis on Infinite Earths, the DC multiverse is destroyed. But, in Infinite Crisis and subsequent comics, it was revealed that the multiverse had been restored/recreated/preserved into 52 other universes, each with their own earth.
Which universes survived as the 52? For example, Earth-3 housed the Crime Syndicate, and this universe was (presumably) destroyed in Crisis on Infinite Earths; does it still exist as one of the 52 earths?