My favorite secret of crisis communication is "Covering Risk".
The article begin with "People’s perceptions of various risks differ greatly", and that is the key for the wh*** thing.
You have to define in which group is every person before you can start the communication.
The article explain very well Risk and its components
risk = hazard + outrage
hazard : if the
risk is deadly. outrage: if the
risk is upsetting.
I think this secret is extremely important because in your shoulders rest the responsibility to get the people understand what you tray to say, managing the different levels of risk and the perception every group have about the subject.
The article of "How do People React in a Pandemic?" said that people can react to a crisis with denial or panic, and this is why the secret of "Covering Risk" is so important. What you say can provoke one thing or another.
If you look in the Manual of Psychological First Aids, you will found that one of the recomendation in working with childern and adolescent is "Match your language", and this is totally apply in Covering Risks with any kind of audience, you have to make people understand you, but for doing that, you have to understand first what are they believing and possible behavior at the situation.