No, permafrost was removed, not thawed. And it was construction related, not climate. Construction removed the permafrost, and heat from electrical systems and

No, permafrost was removed, not thawed. And it was construction related, not climate. Construction removed the permafrost, and heat from electrical systems and occupation have prevented it from reforming. But this also implies that no liquid water was expected, which is false. Even places with permafrost experience surface thaw and runoff. The fact that the vault design included a drainage system proves that above-freezing temperatures were expected. The problem was rain/runoff/melt water freezing too fast once it got passed the entrance, and creating ice dams and similar blockages. Combined with an entrance that is warmer (sometimes above freezing) than the deeper facility (always below freezing), and you start to see the problem, since liquid water flows down. When those problems occurred, the drainage system couldn't function properly, which caused addl flooding. Ice dam removal required humans, machinery, and work, which added heat, which made the entrance warmer... And all of a sudden you have a double feedback loop. It was a bad engineering design, but not because they assumed the wrong temperature(s). And nothing to do with climate change. Climate change is misleadingly implied by the absence of permafrost. Ironically, slightly warmer temperatures might have solved the design flaws, if it prevented ice from forming and allowed water to drain before freezing.