False Alarms of a Kind: Coming Home to Fire Truck in Front of My Building Complex

I was on my way home from the store this evening, walking down West 100th Street, and FDNY Ladder 22 came by, siren sounding.
Then I noticed it turned off North at one point...direction of my place.

Sure enough, when I got home it was out in the street in front of my building complex but everything was extremely quiet.

When I got to my front door this kid said a firefighter had gone into my building and there was smoke. 

There was no sign of any emergency whatsoever so I went in and went up to my apartment...no smell of smoke or anything.

I went back downstairs with my camera and found Dave the Security Guy coming towards me--

He explains as we move along here what was happening

https://youtu.be/6LOz8FskA3A


So many fire runs are for situations like this...Firefighters often go out not knowing exactly what they are in for, of course. Part of the stress of a very stressful job.