Wisconsin Governor Tony Evers declared a state of emergency and called in the National Guard on Friday after two fires at electric substations. The city's utility, Madison Gas & Electric, said the fires had been contained but there were still some customers without power Friday night.

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.

An executive order issued by Evers said the declaration was issued to "provide support during the large power outage that is exacerbated by the extreme heat wave affecting the area," CBS Madison affiliate WISC reported. The heat index value for Madison means temperatures felt like 103 degrees on Friday.

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"Keeping folks safe remains our top priority as we continue to manage and respond to this situation," Evers said in a statement.

A fire is seen at an electrical substation, center, during a heat wave in Madison, Wisconsin, July 19, 2019, in this picture obtained from social media. UW-SSEC/AOS/via REUTERS

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.

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 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.