Cpl. Bowman discovers that her mother has the illness and that her little brother is missing. Her brother, Trevor, is hold-up with his girlfriend, a DJ, and another couple in the small town's radio-station offices. When the infection spreads to the National Guard troops, it is up to Cpl. Bowman to get herself and the few survivors she has with her out of the town.
The most horrifying thing about this film is that it cost $18,000,000.
The film does make a few nods to the original, most obvious among them being "Bud", the vegan Private-turned-Zombie who still retains enough of his former self to follow simple military commands, not attack his living companions (he doesn't eat meat), and to still carry a flame for Cpl. Bowman. "Bub", in the original Day of the Dead, was also a zombie that retained something of his former self and was being domesticated.
Even if you ignore the almost total departure from the original, this still is not a very good zombie flic. At points, the plot seems to plod along, making the experience that much more excruciating for the viewers. There are a vast number of superior zombie films made for much less that would be more worth your time.