The Shuttle Columbia
There was a sort of Gen-X litmus test, where we’d remember where we were when we heard the news that the Challenger had exploded on take-off. It was our generation’s JFK. I was coming out of a physics regents test, and I remember that we were all shocked and disbelieving. We were high school students then.
Times change. All of us have gotten older, and, particularly in the past fifteen months, all of us have heard a litany of disasters, both accidental and purposeful. 
We heard about Columbia at a rest stop on the Mass Pike on our way to Boston. I was disbelieving — Could the cashier have been talking about an unmanned launch for some reason? Didn’t the last shuttle mission land last week? — but not shocked. Unlike our past selves, we now know the shuttle missions are fraught with peril, that the ship itself is built and flown with old, labor-intensive technology, that many parts can break, even if NASA has a thousands eyes watching every possible cog and circuit. There was no shock, just sadness.
When we got back to the car and onto the highway, we tried to get the news on the radio, but we couldn’t pick up anything clearly in between Boston and Springfield, and gave up after scanning the dial a number of times. We finally found out what happened after we got to Grace’s cousin’s, and saw a bit of the CBS broadcast around 12:30. Columbia had broken up at more than 40 miles up, travelling at Mach 12. So fast and so high: in another sign of the times, I mentally crossed out “terrorism” from the list of possibilities. We were busy the rest of the day, and didn’t see the news again until much, much later.