A car crash Sunday morning at a west side intersection caused a natural gas leak, according to a release from the Madison Fire Department. Firefighters were called at 10:35 a.m. to the intersection of Watts Road and Struck Street on a report of a car crash and the odor of natural gas. There were no injuries in the single-vehicle crash, but the driver reported running over a small tree, a natural gas pressure monitoring station and a pressurized gas pipe and then into an Alliant Energy transformer box that services the surrounding commercial district.