Dreaming of everyone dying is a negative sign as per dream meaning and interpretation. The dream means you will soon regret and action of yours. It also means accident to family members or relatives or friends. Dreams of everyone dying happen when you are under the influence of negative thinking. The dream is asking you to move towards positivity.
On symbolic level the dream means people who are helping you or have stood with you will desert you due to misunderstanding or due to some action of yours.
Dream of everyone dying and you see yourself in the dream means you might fall ill along with other people you know or work with. It also means fire, flood or other natural calamities.
Dreams of everyone dying and you are not present in the dream means you will hear bad news about your neighbors, relatives or friends.
Dreaming of everyone dying and you walking around means death due to factory blast or pollution or poisonous gas.