When the Challenger tragedy happened, I was 23 years old and at work that day.
We weren’t watching the launch on TV, as shuttle launches were pretty routine at the time (although the teacher in space aspect added interest to it - interesting about your MIL), but, I always had the radio on. After I heard what happened, and spread the news, someone (can’t remember who) turned on a small TV in their office, and we saw it all.
The Columbia tragedy happened on a Saturday, so we were all at home that day, as it started breaking up over Texas.
We knew about the debris issue during launch, but, many “in the know” seemed to not be too concerned about it.
I have very vivid, sad, memories of both incidents.