>>>Do you know what was the strength of this tornado was?<<<
I think it was an F3. These were well built homes. Homes in most areas of the US are built to withstand approximately 75MPH with no damage (not even shingle blow-offs). But even an F1 is beyond that. It would be cost-prohibitive to design for tornado speed winds, given that the odds of being hit are very, very low. Houses in northern states are built to similar standards as in Sweden for snow loads, but this doesn't help much in tornadoes.
Here's another one last year that hit in Northern Mich. It was almost more overwhelming than structure damage. I stood way up on a hilltop and you could see this 1/2 mile wide path cut thru the forest. It went for 10 miles or so. It looked like a giant took his sickle and just cut all the pine trees off at about 15 feet high.
This had been a dense mature pine forest. The roads had been cleared by the time I got there ....
