A 14-year-old boy in China was killed when his chair exploded, sending chunks of metal into his rectum. The bleeding this caused killed him.
The explosion came from the gas cylinder that was in the base of the chair, the part that allowed the user to adjust the seat up and down. The canister is full of highly pressurized gas, which exploded upwards. In 2007 another chair exploded, propelling a 20cm part into the backside of a 68-year-old man. He lived.

