This is an old tale that has been passed on from generation to generation. Who know's if the cataclysm ever did happen. If it did it certainly was a long time ago. Longer than any of the current races of the Solinia have been around.
Some races speak of a race known as the Tinai. A winged biped race not unsimilar to angels. They existed before the time of the current world and were known to worship the God Methabeht, a God which no race on Solinia currently worships.
Legend has it that the Tinai were forced to evacuate the planet due to a cataclymsic event that resulted in the complete destruction of all life on the planet. For what reason, nobody can remember. But some speak of tales of a particular Tinai named Hiran Asura who turned against his people after he gained considerable power.
The Tinai are believed to have existed in a magestic capital city in a continent that nobody has been able to locate. Perhaps it has long sunk or been washed away by the sands of time. Some believe that this city left the planet and entered the heavens where the Tinai still live. But maybe this is just rumour...