A gas line explosion levels several buildings in Sun Prairie killing one firefighter. The incident occurred in downtown Sun Prairie Tuesday night. A contractor struck a natural gas main shortly before the explosion rocked the Madison suburb of around 30,000 people. Crews were called at 6:21 p.m. for a report of a natural gas leak at the corner of Main and Bristol Streets. After police and firefighters arrived to investigate the source of the leak and close off the are the building exploded. The blast leveled several buildings. A plume of smoke shot into the sky as debris rained down and cars parked nearby ignited. Two firefighters were taken to a hospital and one police officer was treated at the scene. One of the firefighters later died and another is in critical condition. A couple of civilians suffered minor injuries. The Barr House and Glass Nickel Pizza were heavily damaged.