Solar apocalypse. Fear of nuclear war means that an Endwar style nuke defence shield is built. However, this shield cannot absorb directed energy, and so, solar powered lasers are mounted on satellites by the newly established UN peacekeeping force, making most war obsolete, since the baddies can be vaporized. A group of terrorists, seeing that they can take control through these satellites, launches a massive attack on the secret base the satellites are controlled from. While trying to hijack the system, something goes wrong, and failsafes (kill everyone, zap everything) are engaged. Billions die as roughly fifty satellites blast away cities as fast as they blast individuals. Now, people are trapped underground, and the surface of the Earth is a dead, scorched hell.