An explosion rocked the downtown area of a suburb of Madison after a contractor struck a natural gas main, sending an unknown number of people to hospitals, authorities said.
No deaths were immediately reported.
Sun Prairie, a community of about 30,000, was shaken by a blast about 7:15 p.m. that sent a large plume of smoke and flames rising from the downtown area.
WE Energies spokeswoman Cathy Schulze said a contractor hit a gas main ahead of "a possible explosion." She said the utility's first responders were in the area working to shut off the flow of gas and make the area safe.
Dane County Sheriff's Office operations manager Paul Logan said some people were taken to hospitals, but that no deaths had been reported. Logan said the sheriff's office evacuated its communications center. He had no other details.
Firefighters from Sun Prairie and surrounding communities responded to the scene. Police blocked off downtown streets from traffic and onlookers. The area has several businesses including bars and restaurants.
Steve Owen, 60, who owns Sun City Cyclery and Skates in downtown Sun Prairie, said he saw firefighters and police officers on the street and then the explosion happened. He said the building across from his shop "literally lifted up."