After a comet releases a mysterious virus that begins to kill all of the women in the world, a young couple's relationship is severely tested. They hide out (from both the illness and the savages who hunt the remaining women) in their over-sterilized apartment. Ultimately the duo escapes their self-imposed quarantine to head to the wilderness.
A news report is shown stating that a research facility housing uninfected women has been bombed, killing many if not all of those inside. The bombing itself is not nuclear, nor is it shown graphically
Ostensibly, yes. After over a year of living under strict quarantine, the main female protagonist knowingly exposes herself to the toxic ash and becomes sick and dies as a result.