Man Accidentally Lights Sewer Gas With Firecracker.

http://www.youtube.com/watch?v=XIBeiwfwkmY&feature=youtu.be

Man sticks firecracker in hole of manhole cover to steady it before lighting. His kids stand well back. He lights firecracker and accidentally also ignites the methane gas seeping out of the manhole cover from the sewer below. Poo poo gas goes boom boom!