The storm that nearly downed their airship had been only one among many, dumping rain, snow, and ice across the north. The snowpack that in part gave the Crystals their name, already generous, had built up considerably. Unobstructed summer sunlight had followed, warming and softening the frozen layers. Crews who normally monitored and dealt with that build-up, sending up weather ponies or lofting explosive charges with their mortars to bring it down while it was still small, had evacuated in the face of uncertainty and chaos. The overburden thus was left to accumulate until it reached the breaking point.