10 Comic Book Catastrophes That Killed Millions
6. The Genoshan Massacre - New X-Men
Death toll: 16 million
That's a whole city getting destroyed. Now, how about an entire continent? When Grant Morrison and Frank Quitely decided to bring Marvel's mightiest mutants kicking and screaming into the 21st century, they didn't pull any punches. Heck, one of the early issues of New X-Men saw Charles Xavier putting a gun to his head and threatening to blow his own brains out if a psychic attacker didn't quit occupying his thoughts. That's pretty hardcore.
The attacker in question was Cassandra Nova, Xavier's evil twin whom he thought he'd killed during a psychic battle in the womb. Somehow she survived regardless, and held a deep resentment against the mutant race ever since, which inspired her attack against her brother and his X-Men. It also caused her to wage war against mutantkind as a whole.
To that end she redesigned the Sentinels to be even better at their lethal job than ever before, and then let them loose on Genosha, the utopian island nation off the African coast that served as a place for mutants to live free of prejudice or fear. At least until the entire island was reduced to rubble and its mutant population was slain by Cassandra Nova's Wild Sentinels, with very few survivors.