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It’s kind of got some “jet fuel can’t melt steal beams” vibes to it. The beams didn’t melt. The fire was just intense enough that it caused the tempered hardening to fail. Without which, they could no longer sustain the load of the rest of the building above it.

Architectural materials are designed to deal with typical loads, plus a decent margin of error. Most people don’t have beavers in their walls, so bite force isn’t a typical load. Neither is a fully-laden jet airliner crashing into your skyscraper.

In my state of Victoria, in Australia, it’s required to use steel frames for construction of homes in bushfire-prone areas. Fire is a typical load that meeds to be engineered for. However, a single-story house (we build out instead of up when there’s the space) doesn't need hardened steel beams, and without 100 floors to support it won’t collapse in a fire.