For disasters, you have to give people instructions on what they can do proactively to prepare themselves. This "activity-based" messaging will help them both physically and psychologically get through an event. I always say, "The mental to the physical is as 3 is to 1." The physical act of becoming prepared will lessen the worry that is sure to descend on many.
Now is a great time to leverage that energy, be it worry or concern, for positive disaster preparedness activities. Here on the West Coast where the "normal" disaster preparedness message is to "be prepared for two weeks, and not three days," this COVID-19 is a godsend for more extensive preparedness among people and organizations.