The Pittsburgh gasometer explosion, or Equitable Gas explosion, was a bizarre accident that took place in Pittsburgh, Pennsylvania on the morning of November 14, 1927. A huge cylindrical gasometer, the largest in the world at that time, developed a leak, and repairmen were sent to fix it. The repairmen used an open flame blowtorch to find the leak. This turned out to be a serious mistake. The leak was found, but the tank full of natural gas then floated into the air like a balloon and exploded, causing a rain of fire and metal over a one mile radius.