Nine-Tailed Demon Fox's Attack

After the Third Great Shinobi War, the Nine-Tailed Demon Fox attacked Konohagakure. It is possible it was summoned by Madara Uchiha. The Fox created havoc and destruction in the village, and it killed many shinobi, including Iruka Umino's parents. It was finally stopped when the Fourth Hokage used the Dead Demon Consuming Seal to seal the Demon inside his son.