The Blackwell F5 tornado struck Blackwell, Oklahoma, on May 25, 1955. The 400-yard-wide wedge tornado carved a path through the town, killing 20 people and injuring over 200. The damage was immense, destroying 400 homes and leveling 60 businesses. As noted by Wikipedia, it “destroyed or swept away at least 400 homes and caused damage to approximately 500 other homes." Beyond destruction, the twister is famous for rare electromagnetic activity. “The tornado's electrical activity was unusually vigorous,” reported Reddit. Many reported a steady blue light near its base resembling an arc welder., most likely caused by St. Elmo's fire.