I was in high school. I didn't see it happen live, but it was announced over the PA system that the Challenger had exploded.
I'll never forget that day.
I,too was in high school, my senior year. It was at Middletown Christian School. The principal, I think it was, walked in, and told all of us, that the space shuttle had exploded.
Many of the students began to make jokes about the accident after that, like "how many astronauts can you fit into a volkswagen, 4,and 7 in the ashtray", and such, like NASA, now stands for "need another seven astronauts",but I was disheartened by the incident, I was(and still am) a space exploration fan, and knew this would effect the program, maybe even end it, if some had their way, not to mention the loss of the crew.
I went to work after school, to a grocery/department store where I worked in Lebanon, Ohio(I lived there then,too, and still go there on a regular basis, it is around 30 minutes from where I live now), and the tv's on the display endcaps were still showing the accident, and the aftermath, of news reporter comments, and that was around 4;30, or so.