I remember I was working & heard it on the radio right after it happened. My former roommate Dave was (& most likely still is) a huge NASA buff, he'd taken a trip to FL a couple years earlier to see a shuttle launch firsthand. So I immediately called him & broke the news to him. He knew the names of everyone on board.
Coincidentally, or perhaps not, PBS is airing the first part of a 4-episode doc on NASA and the space program beginning tomorrow (Tuesday) night and continuing for the following three Tuesdays. Looks pretty cool except it's making me feel just a tad aged, in that things that happened during my childhood are now the subject of historical PBS programming.
And as for where we were when the Challenger blew up, I was working my post-collegiate slacker job as a gardener in Sacramento, and our boss drove up and told us about it. Didn''t get to see any footage of it until later that day, but it was pretty mind-blowing when I did.
I was in Paris when the Columbia accident occurred, and it got as much saturation coverage there as we'd have seen if we were at home.