Earth-96 (Pre-Crisis)

Earth-96 was one of the many universes in the Original Multiverse. It was destroyed during the Crisis.

Attack by the Joker
At some point, the Joker gassed the Daily Planet, as he felt that he wasn't covered enough by the paper. This attack lead to the death of at least 48 of their employees.

Trivia

 * This Earth was originally called "Earth-6" during pre-production for Crisis on Infinite Earths.