I'm glad you made it through, Husker, though I'm sorry to hear your parents marriage didn't survive the aftermath.
This night was anything but 'usual' in any respect. Seven tornadoes in less than 3 hrs - and one an F4 - in an urban area is exceptional.
I've attached a few links I think covers a few different aspects, such as an engineering study of the types of damage on different types of structurs, the NWS archives, which have some terrific photos attached and a link that includes what it was like for the kids (before,during and after).
Photo from the above link.
The Engingeering Analysis:
And, a link to "The Real Night of the Twisters."
Let us know if you find any other info that you think would be of interest here, Husker. Good thread!