Story Setting Idea:
Earth has been overthrown by aliens. These aliens have polluted our air to make a suitable environment for them and a deadly one for us. However, some humans can tolerate the new living conditions. Those who can, fight on the ground.
Everyone else is typically thrown in underground shelters: a hundred or so floors each. The lower you are stationed, the less time you can spend on the ground. No one lives osn floors 90-99 as those are supply floors. Far from pollution, safe for everyone to eat, and protecting those at floor 100. Floor 100 contains the ruler of the bunker and everyone who could barely live any higher up.
People don't hold special occasions or funerals. Special occassions aren't allowed as they often call for a surplus of food. Funerals could be minor, but not many people want to see their stripped love one get placed on an elavator shaft with other dead people. They don't like seeing the corpse get sent up for aliens to feast one.
Also, crime is barely allowed, they punish harshly. If you break a minor law, you get stripped of half your portions for a respectable timeframe. If you commit a large crime, you get placed on the shaft, with corpses or not, and are raised up. That is, if you're older than 16. Anyone younger gets placed into a conditionary schooling and are disciplined harshly.