How could my actions affect how my child reacts to a tragedy in the city?

Directly: Children look to adults/parents for cues and clues on how to react. They need to understand at their level what is going on. Do not suppress your reaction as it is honest and real. However, provide your child with age- appropriate cues and answer questions honestly. They know when something is tragic as well and they need to feel safe. (i hope other mds will expand this response.).