Avenhelm is an important trading city on the Agras Plain, and serves as a vital link between the Agras and Agalu rivers. Known since ancient times, it became particularly infamous during the mid Sixth Age when much of the new city was destroyed by a catastrophic landslide.
During the Alliance era, the city began to expand. As it was still a vital trade artery, there was little need for food production locally, so the old terraced hillsides were slowly replaced by suburbs. The area had been surveyed extensively for geologic stability, and no problems were found. However, in A.Y. 6489, the town was visited by the dragon Hrethrel Jusenkyou, who warned them that the slope of the northern mountain would collapse, and that they should cease building there. He went so far as to inform them of the exact date and time, and returned to the area on several occasions in the coming years.
While many residents did leave, the city council took little head of the dragon's warnings, and the area turned into a sort of slum. The land was undesirable and very cheap. In addition to run-down housing tracts, many shelters and halfway homes for the city's homeless population were established there.
Four days before the predicted collapse, Hrethrel arrived with thirty six other dragons from High Mountain, and began organizing the orderly evacuation of the area. When asked to stop, he sent for additional dragons from the nearbye Seacrest Spire, whom claimed Avenhelm as part of their ancestral homelands. The show of force was enough to allow Hygelic's efforts to proceed, and by the date he had predicted, one quarter of the city was completely empty. With much complaining, the council also shut off city services such as water, power, and gas. Most of the residents were able to gather their belongings ahead of time, and some businesses even had remove valuable fittings.
The actual collapse happened within an hour of Hrethrel's prediction. Hundreds of cameras were trained on the mountainside, so it was captured from many angles and at many speeds. When the dust finally settled, one fourth of the city lay in ruins. However, there was not a single injury or fatality, save one camera man who was briefly hospitalized for dehydration and sunstroke.