When a town on the corner of the Mediterranean is stricken with an outbreak of the plague, death is a main concern. Everyone is forced to live as though their life may be snatched from them at any moment. The Plague makes the point that, really, this isn’t that terribly different from normal life. After all, we could all die at any moment. The difference, however, is consciousness. If we live as though a roof tile may fall on our heads at any moment (props to Kierkegaard for the example), we will no longer play passive victim to suffering and death. We will live while we can. Until we die.
Tarrou’s picture of the world, in which death is always murder, is oversimplified and proved erroneous by the novel.
It is not the actual deaths caused by the plague that make it such a horrific experience; it is the fact that death is made concrete rather than abstract for the citizens of Oran.