A 17-year-old Utah boy cutting the grass ran into a canister of TNT.
Taylor Wood says he heard a thud as the mower hit something solid in a pasture behind the family's home in Hooper, Utah.
He saw the words "TNT shell" on the side, and his mother called authorities.
Officials say the potentially explosive shell could date back as far as World War II.
The Weber County sheriff's department took it away for safe disposal.
