Fire marshall/AHJ (authority having jurisdiction) Scott Strassburg shared an eye-opening series of photos that demonstrate the importance of a fire door (and appropriate hardware).

The photos were sent to iDigHardware.com who added that the fire was a result of a cooking fire that reached the wood cabinets and spread from there.

“As the tenant escaped from the apartment where the fire began, the door between the apartment and the corridor was left open, allowing the fire to spread into the corridor.
 
At the ends of the corridor, there were two fire doors – one leading to a stairwell (very close to the apartment where the fire originated) and one that was a horizontal exit leading to more apartments. These doors were both closed and latched, and prevented the fire from compromising the egress routes from other floors.”

 

[h/t reddit]

 

 

 

 

 

The apartments which opened onto this corridor were directly affected by the position of the entrance doors – when doors were left open during the evacuation and subsequent firefighting efforts, the fire was able to spread into the apartment. When doors were closed and latched, the apartment suffered much less damage. If building occupants were behind these closed doors, the doors would have offered some protection from the smoke and flames – this is very important since the egress route from these apartments was not usable. [source]