RED DEER, Alta. - Joyriding thieves in Red Deer, Alta., stole a monster-sized dump truck and used it to chew up ball fields in an athletic park.

RCMP say the thieves somehow managed to start the giant vehicle, which has a maximum gross machine weight of 161 tonnes, and then drove it off of a flatbed trailer.

It was enroute to the oilsands region in the Fort McMurray area.

The vandals used the monster truck early Saturday morning to rip through 120 metres of chain link fence and flatten six out of eight dugouts, as well as damaging the playing fields.

Police estimate the damage could reach $1 million.

The only thing that stopped the truck was an oil leak that caused it to stall on one of the ball diamonds.