SUN PRAIRIE (WKOW) — A group of Sun Prairie residents has filed a civil suit to recover losses they say they incurred during the gas main explosion a year ago that killed a firefighter and leveled a large portion of downtown. Nine homeowners filed the suit Aug. 2 in Dane County Circuit Court against contractors VC Tech, Bear Communications, Verizon, WE Energies and USIC Locating Services. The …