Geological / environmental event
Major flood inundated the valley of the River Gathe and destroys the Old Empire's bridge at Gathebridge.
The winter of 401 was exceedingly wet, and on the last day of the year, a major storm blew from the north, driving water into the Abgathe. The waters of teh River Gathe rose and the Old Empire's bridge at Gathebridge was submerged. Sea-water flooded into Ysni's lake and water levels rose all the way up to Ysni's Ford and beyond.
When the levels fell, the bridge at Gathebridge was gone, the burned ruin at the Great Temple of Gathe was cleansed and the River Gathe renewed.