Originally posted by FrothByte
Prove it. Are you even sure it's pure stone?
Assuming it is a 1.5 foot thick slab and a rectangle, the slab's dimensions would be 1.5 ft×9 ft×10 ft. to fill the tunnel. 135 cubic feet. The density of what is considered medium density limestone is 160lbs/cubic foot. This gves us a weight of 21,600 lbs. The average city bus weighs in around 20,000 pounds empty.