MADISON, Wis. -- Fires at two transmission substations in Wisconsin's capital on Friday knocked out power to thousands of customers on the hottest day of the year to-date, sending dual plumes of thick, black smoke into the air and shutting down government buildings, courtrooms and businesses, and leading the governor to declare a state of emergency.
No injuries were reported as a result of the 7:40 a.m. explosion and fire at the Madison Gas and Electric main power center a few blocks from the state Capitol, which was among the buildings that were forced to close. A second fire at a substation near the University of Wisconsin-Madison, a couple of miles to the west, prompted the evacuation of nearby buildings. No injuries were reported as a result of that blast, either.
At its peak, more than 13,000 people were without power. While there were fluctuating numbers as power was being restored, nearly everyone had power back on by Friday evening.
Gov. Tony Evers declared a state of emergency in Madison and surrounding Dane County. The declaration authorizes the activation of the National Guard if necessary and directs state agencies to provide assistance. The Guard had not been activated as of late Friday afternoon.
"Keeping folks safe remains our top priority as we continue to manage and respond to this situation," Evers said in a statement.
The Capitol closed, but it did not affect the Legislature because it is on a break for the summer. The city-county building across the street from the Capitol also closed and the Wisconsin Department of Health Services, which is around the corner, sent employees home and directed the public to leave the building because of the lack of electricity.
All state court system offices in downtown Madison, including the state Supreme Court and Court of Appeals, also closed because of the outage. Public access to some court system electronic services, including the Wisconsin Circuit Court Access website and electronic filing in some counties, was also down. Traffic lights were knocked out throughout the downtown area because of the outage.
Residents with no access to air conditioning were advised to be on alert as the National Weather Service issued an excessive heat warning for the area Friday, with temperatures in the 90s and high humidity. Shelter was available at the Kohl Center, where the UW basketball team plays, on campus.
Public Health Madison and Dane County officials advised all businesses, including restaurants, that don't have emergency backup power sources, to close until power was restored.
Zane Geyer, a construction worker working on the seventh floor of the downtown Gebhardt Building told the Wisconsin State Journal he saw the first explosion.
"Flames went about 150 feet (46 meters) into the air," Geyer said. "The fire kept getting bigger, and the transformers' oil inside probably fueled it."
Geyer said there were three or four explosions after the first one, as transformers blew.
Utility officials said they had not identified the cause of the explosion, but they had ruled out heat and were looking at mechanical issues.
In a late afternoon statement, the city said the Madison Fire Department had to use a foam that's often associated with contaminants known as perfluoroalkyl substances, or PFAS. The city said it's not clear whether the foam actually contained PFAS, but it is being tested and steps were taken to lessen the spread of water and foam.
Two environmental engineering companies have removed hundreds of gallons of water from the storm sewer in two areas, and the water will be tested. Barriers were installed to curtail water run-off and soil will be removed as part of the remediation process, the city said.