https://capitolnewsillinois.com/news/illinois-is-experiencin...
https://www.scientificamerican.com/article/watch-out-tornado...
There were small, weakish tornados west and south of Chicago, but by the time the storm got to Indiana it had morphed into a 20-mile wide derecho with 100mph wind. Since there has been a TON of rain recently, it was easy to knock trees down, and as you said that area has a lot of power lines above ground.
There really isn’t a lot of damage to houses and buildings, it’s just that there are downed trees and power lines everywhere, all at once.
https://www.instituteforenergyresearch.org/the-grid/pge-to-b...
https://corporate.my.xcelenergy.com/s/transmission/about/ove...