The story opens with animal loving, stay-at-home mother Naomi witnessing the first death while out shopping. After which things rapidly get much worse.
The writing is very readable throughout and well edited. Several characters are followed as they deal with the disaster and its aftermath. Some are stronger than others, but all the plot threads are interesting.
The kinds of things that happen in the aftermath of the disaster are somewhat predictable and I was inclined to pick holes in the premise, but even so, the story gripped from start to finish as engaging characters faced life-and-death problems.
This is the beginning of a series, but it works reasonably well as a standalone book. Not everything is resolved at the end but all the characters have made some progress with their problems, so I felt the ending was satisfactory though I would have been happy to keep reading.
As you might expect, features a lot of death, corpses, and violence including rape. YMMV, but I thought the subject matter was sensitively handled.