Glass Shattering
Workers were diligently placing an oversized glass sheet inside the elevator in this elevator camera footage. They even thought to include a small stand for support. However, they didn't quite think things through.
The glass sheet was too long to fit comfortably within the elevator's confines. The glass was yanked upward as the doors closed, and the elevator descended to lower floors, resulting in a catastrophic shattering event. Boom!