This is correct. This is why when people say, "but muh steel building", is dumb. Each design brings significant differences. This specific issue is why fire retardant spray is a REQUIREMENT for structural integrity of the building in fires. Additionally it's rating only lasts for specific durations at specific temps. The fires well exceeded the safety margins. Never mind it was over due for replacement and well documented as fraudulently installed (never up to code) in the first place. Additionally, much had come away from the structure, which is why they were due for a complete re-installation. Which was a requirement for their continued insurance coverage.