I have two from my childhood. The first was the attempted assassination of Reagan. I was home from school, watching cartoons. I remember being very upset that they interrupted Tom and Jerry with the news report. I was 10, give me a break I remember the stock footage, but I really wanted to watch T&J (this was old school, full violence, and rascist T&J, not the modern pablum).

The second was the shuttle Challenger explosion. I was at a friend's house, it had snowed in Atlanta and we had the day off from school. Snow is not a common occurrence in the ATL, and we had gotten quite a bit, enough for kids to play in. We came inside to get warm, and turned on the launch. I had a bit more awareness at this point, plus I was a geek, so it was big news.