Invasion of the Red Dragon

"Invasion of Red Dragon was one of the mass destruction happened on Tonikia, 15 years before the series (Horsehoe continent)."

Why it happened?
"Capital of the kingdom was Stonehall, city economy was much from its nearby mines. One cave which was found last, was the beauties. There was a big amount of unknown minerals which were considered, if exploited, they would be really profitable. So people begun more often to come to this cave, to mine the mineral, without knowing what was lurking there. Former runecarer knew there was a dragon, and that its not good for them to be there so much, so he spoke to king. King did not intend to order people to leave the mine, he wanted more money in kingdom, he was hungry for it. Everything went down, when one miner get more deeply in the cave. The dragon woken, and burned everyone in the cave, but, not only there. He left the cave, and flew to city. Faithful people still think it is a gods wrath, which sent the dragon."