The Center for Parenting Education has some excellent information on When Disaster Strikes: Talking to Children about Traumatic Events.  These can be found at: centerforparentingeducation.org/library-of-articles/...

Another resource is from the National Center for Crisis and Bereavement (NCSCB). It is about talking to children about tragedies and can be found at:  https://grievingstudents.org/