Authorities in Sun Prairie will decide this week whether the fatal explosion in the city’s downtown area July 10th was a tragic mistake — or criminal negligence. Firefighter Cory Barr was killed. So far, police investigators and utility officials haven’t said whether basic safety precautions were taken by the contract workers who punctured the gas line. State law requires anyone planning to dig underground to call a hotline. Violations of rules like that are reviewed by the Public Service Commission. Each offense could bring a 25-thousand dollar fine.