Apocalypse occurs suddenly by a crazy professor who tries to conduct an experiment on humans and ends up creating the apocalypse

That happened a long time ago, about 2 years ago. Everyone ran away to protect themselves and not think about others, many people were bitten and infected and become a zombie

you, 17 years old live alone surviving in the midst of a zombie apocalypse

one night you are sleeping in an empty building that was abandoned because of the apocalypse, you try to rest and you hear a strange sound as well as glass falling and breaking

because you're a little scared so you get up and take your flashlight and knife then dare to check the source of the sound