Idiot Plot: The only way half of the situations in this movie are able to happen is because people behave like brain-dead morons who don't know what the word "fire" means. Of course, this is how many people behave in disaster situations in real life, so it is arguably justified.
Seinfeld Is Unfunny: Considering how this was made in the 1970s, one can probably see it now and wonder why the hell modern conveniences we have today aren't being used. A lot of these "modern conveniences" for fire safety, such as sprinklers, were already common in the '70s, but the builders did skimp on them in the film to save money. Many cities tightened their building codes after the film came out to require sprinklers in all high-rise buildings. The elevator scene and several action stunts probably look incredibly corny. Heck, even the concept seems pretty stupid today.
Though, there were a few comparisons made between this movie and real-life events when 9/11 occurred.
Tear Jerker: Lisolette's rather thankless death even bothered test audiences, though it sets up a very bleak Downer Ending for another character.
The firefighters taking heavy casualties and fatalities, and yet they can't fight the fire effectively.