AP reported 10 June 2011, Half the country wilts under unrelenting heat:

Detroit officials intentionally cut power to city hall and a convention center Thursday to prevent the municipal power system from crashing from high energy demand — even though temperatures had tapered to the 70s after two days above 90. Equipment failures knocked out power to several other government buildings and traffic lights in parts of the downtown.

“Because there was a short window of time, we had to make a decision to take some of our customers off to prevent a blackout of the entire city,” Detroit mayoral spokeswoman Karen Dumas said.

Too bad they didn’t have solar, which would have provided peak power at peak load.

-jsq