My dad was a racecar driver when i was a kid. He always carried one of those pancake air tanks on the trailer. One day he filled it up and stopped to BS with a guy and sat the tank down. I went on ahead to the house, i was about 15. A few minutes later he picked up the tank and it blew removing flesh from his right leg. The tank had blown open from top to bottom and looked like a big pillow. He spent the next week in the hospital. That had to hurt...Bob