Our Duty Truck and a Chief were dispatched to a report of a Power line down in a busy intersection in our town. Upon arrival we found a transmission line down on the ground and arcing. We immediately shut down the intersection and kept people away from the area. Our dispatch contacted the Power company. As we were securing the area a PD unit (Police) pulled his car approx 50 feet from the line to block the road, As we noticed this and were telling the officer to move his cruiser the power line arced and caught a steel light pole and began arcing and burning throwing hot molten steel from the line around. As the officer dove behind his car and we moved back even further we noticed a traffic control box on the opposite side of the road smoking. At this time we realized that the power line was energizing all the steel traffic light poles & light poles as they were all connected underground by wire. Our truck was under a traffic light pole and people along with some our duty crew was close to if not touching this poles. We then evacuated the entire area and stood by and continued to secure the area and keep the fire light box from spreading. Once the power company arrived they secured the power and we checked the entire area for fire extension. Upon examining the area where the line arced it was noticed that the line had burned deep holes in the blacktop and concrete as well as the steel pole. This incident just goes to show that there is no such thing a ROUTINE CALL and we need to be aware of our surroundings and what is happening at all times.