It is common to see emergency vehicles in this neighbourhood, but rare to see fire engines on Lebreton. They're much more common a block over on Bell Street. I lived at 211 Bell from July 1986 to July 1987. There were a lot of fire alarms there. So many that people usually waited for confirmation that there was an actual fire before leaving. Some people didn't leave even if it was a fire. During my last week in the building we had three alarms and two were for actual fires.
If I had my camera with me during one of them, I would have been able to show you a photo of smoke pouring out a fifth storey window and people on a fourth floor balcony watching firefighters climbing past them to deal with the fire.
I don't think these trucks on Friday night had a fire to deal with. Bells were ringing inside the building, but the people on the sidewalk didn't seem especially worried.