Based on the several articles I read on the fire, the primary issue downstairs was that the fire and smoke moved exceptionally fast fueled by a decade long accumulation of junk, no clear pathways to the exist, and doors that opened the wrong way. There were reports of fit sober young adults who lost track of friends in seconds in the smoke, and clearly unimpaired people were unable to escape. Given the available information, ANYONE who escaped was damned lucky. All those upstairs had virtually no chance to escape.
What bothered me most was the reality that the city had received apparently dozens of reports detailing code violations, but inspectors repeatedly left just because no one opened the door. Worse was the fact that there is no record of any inspector entering the building in more than thirty years. There are tens of thousands of old warehouses across the country that have been “reused” in creative ways, some probably as bad as this death trap. Too sad.