Great Hole in the Sky

Was a massive hole which was torn in the thin fabric which protected the world from the complete wrath of the sun. The Ancients became very careless and pumped massive clouds of poisonous gasses into the sky, which ate away at the fabric.

When the hole was finally torn in the fabric, the sun began to mercilessly beat down on the surface of the world, reducing much of its lands to radioactive wastelands. The sun also melted away all of the worlds remaining ice caps, which rose the sea levels and triggered the Great Flood.