I think a neat addition to casualties would be some graphs of casualties, over all, and by region. If not something you create maybe a fan can take some numbers, and work them up, but it would help (at least me) feel the emergency, gravity of the situation.
And or bring back news, or shortwave broadcasts to give for the same reasons.
It is your story to tell, and I am happy you are able to create it at all.
I think it adds to the gravity of the situation that the characters (and readers) know that a tragedy is occurring, but have no idea how many survivors there are or who made it to shelter. From a literary standpoint, not having critical information adds to the element of suspense and dread, allowing the characters and readers to alternate between irrational extremes of hope and fear.
And or bring back news, or shortwave broadcasts to give for the same reasons.
It is your story to tell, and I am happy you are able to create it at all.
Sort of dreading the end game. Satisfaction that ol’ dead eyes gets what is coming? Or he wins?
Enjoying the vignettes for sure!