Your forces were out on a routine patrol and the undead were suddenly everywhere! Your forces were badly depleted in the conflict thus you must continue to do your job and keep the undead population under control until a solution can be found.
A Soviet soldier taking part in the Battle of Stalingrad in 1942. To purge the city from the invading fascists, you got rifle, grenades and you can call backup. Make use of the reinforcements at your disposal.
Survive the night fighting off zombies from your barricade. Survive longer than a day by making use of the daylight hours effectively by repairing your barricade, searching for weapons and looking for other survivors to help repair and defend.
Nobody pays attention to a meteorite fall in the jungle and a few years later, military satellites discovered strange activity in the jungle. Your government sends elite commandos to find out what is going on and to try and clear up the situation..