In our school system, the middle school building is divided and one section is "upper elementary" (4th and 5th graders) and the other section is middle schoolers. The high school is dismissed first, then the middle school and upper elementary, then K-3. Apparently parents held up by the train called the teachers at the middle school to notify them that they would be late. Then there was the discussion on the bus of various stories traveling the grapevine. One of the rumors was that a young child had been hit. Other rumors were saying that a car was hit on the tracks.
The questions are sometimes very hard for me to have to answer. I don't want her to have to know about these bad things in the world. But I'd rather she hear it from me where she can calmly process it than to get worked up by hearing rumors at school. I let her know that I didn't think it could have been a young child walking home from school because of the time. Later, when the news confirmed it was a high-schooler, I did let her know that it was true that a high-school student was hit and killed walking on the tracks.
I believe that its important to let kids learn to experience these hard parts of life in an age-appropriate way as they grow. A child who has been totally kept away from these things and then suddenly has a tragedy that hits close to them is much less emotionally prepared to deal with that situation than one who has been gradually exposed to these things and learns that life moves on and people move forward and we celebrate the good where we can find it.