Boomf

http://www.youtube.com/watch?v=gryuusTmucM

Someone just let a firework off inside?

haha I forget whats in it, but its a felony and its unstable. if it gets wet u could drop it and go boom. that was the size of a ping pong ball. and it left a small crater and peoples ears were ringing. next should be a tennis ball sized one.