Miylian Meteor

"The Miylian Elders blamed the Dragons for the meteor that destroyed one of their cities. This escalated into the Miylian Elder Dragon War."

- Miyla History Textbook

Before the Miylian Elder Dragon War, the Miylian Elders were the ones that looked after Miyla the first homeworld of the elves and the homeworld of the dragons. Since the dragons maintain the portals between worlds most of them were never on Miyla so the elves took care of the world while the dragons where gone. Since the dragons spent so much of their time in space maintaining the rails that the portals run on. When a meteor came and destroyed one of the elves' cities the elves blamed the dragons who were in space and could have stopped it. Dragons explained that they were working on the portals and were too busy to notice the meteor that hit the planet. The elves argued that the dragons should have been more concerned about the planet because that is where their nests and families are. The bickering escalated to the point where the dragons and the elves went to war for control of the world that ended with the elves fleeing to Shinia.
The reason why the meteor did not destroy the world is that the elves that saw the impact of the meteor cast wards around the villages and other structures. Since the elves are the most powerful of the mortal races their wards were able to protect their civilization.