It appears a backhoe at a city works site is the cause of a natural gas leak in the city today. City official Darrell Matson says the sewer and water crew was doing maintenance on Red River Road and Rupert and that the tire of the backhoe hit the gas line. He says the extent of the damage is not known The leak forced the evacuation of several homes and buildings in the Mariday Park area for much of the midday and forced the closure of Red River Road.