Sucks for the farm owner...
A bunch of cows nearly lifted the roof off their barn when their farts combined and activated. According to AP, the explosion was caused by the methane released in their gas.
Police say that a static electric charge triggered the detonation, and a spurt of flame, at the farm in Germany. The roof was slightly damaged and one cow suffered minor burns but no humans were hurt.
Ninety cows were kept in the shed and it wasn't clear why enough methane had built up to cause the explosion. Bovine burps and flatulence release large quantities of the gas.