In the article tied to the archive TV news report about the Space Shuttle Challenger explosion, the incident is called "the beginning of the age when the whole world knew what happened as it happened." The main reason why this tragedy earns that distinction is because many schoolchildren were watching the launch live since the shuttle would be carrying a teacher.
As a member of Generation X, of course I remember where I was when I found out: seventh grade, sixth period, biology class. I did not see the live telecast. I don't know if anyone was watching it in the junior high school, although it would make sense for a science class to have it on.
The details are fuzzy. Given the time it occurred, chances are I was at lunch or in one of the home economics classes. (The rotating series of courses--typing, cooking, sewing, metal shop, and wood shop--wasn't called home ec, but the name escapes me.) The biology teacher told us what happened. Random remembrance: I think we were studying reproduction that day.
If the explosion happened at 11:38 a.m., I didn't find out about it until sixty to ninety minutes later. For 1986 that certainly would have been fast-spreading news, especially inside a school's walls. Think how slow that would seem today.
Rewatching the TV news report above, I'm struck by the relatively leisurely cutting compared to the style of today. Perhaps the nature of the story slows it down, but I'd venture to guess that the pace is typical of that time.
To end on a lighter note, here are The Today Show anchors in January 1994--or so the clip info says--trying to figure out what the internet is and how to read an e-mail address. In fairness to Bryant Gumbel, the @ is a lowercase a in a circle, possibly because the symbol wasn't in the graphics program at the time, which is revealing enough in its own right. That said, the woman who isn't Katie Couric knew what it was.
As funny as this clip is now, seventeen years ago I think I would have been just as bewildered as they were.
Update: Although I referred to what happened to Challenger as an explosion, National Geographic says that it is a myth that the shuttle blew up. The problem is that it was often characterized as such in reports, and it certainly looks like that's what happened. The article clarifies it as breaking apart.
The article also claims that reports of those who watched this incident on live TV have been greatly overstated.