Cloak's Fall

The Cloak's Fall was one of the most devastating disasters to occur on the Cloaked Mountains. Due to a convergence of magic on the mountains, a perpetual cloud cover, which raises and lowers at random intervals, was created. This has resulted in extreme flora, fauna, and most importantly, weather in the region. There are no sentient inhabitants there, only a few research stations on the outskirts of the cloud cover. When the clouds raise or descent, large disruptions in local weather patterns occur. The Cloak's Fall was a massive crash of the cloud cover above a large section of the area.
One hundred years after the accidental creation of the mass of clouds, called the Cloak, what was thought to be a regular drop occured beginning on the northern side. While normally, the cloak would descend at once in a mass, this was different. Eyewitnesses described the Fall as if a blanket had slipped off of a bed, with one side of the cloud cover slowly dipping downward, followed by a massive high speed crash of the rest as the Fall moved south.
As the clouds crashed downward, they flattened the area underneath them. Both flora and fauna were crushed, destroying the land below. The crash fully exposed the magical core of the Cloaked Mountains first time, allowing researchers a brief glimpse into the magic that sustains it. 
After the initial fall, the cloud remained on the ground for two days before suddenly rising as though in reverse of the fall itself. The clouds ascended to a height of one hundred meters and hovered there for one week. It was at this time that scounts were sent into the fall area to assess the damage. There, they cound not only the destroyed landscape, but a new type of black glass embedded in the ground. These samples have never been seen again and have been the subject of intense study since the Fall.