Fire Cover
At SFO, there are a few fire houses. Basically, we have 3 alert levels. Depending on the level, depends on how many vehicles stage themselves. Alert one is minor situation, alert 2 is basically a more seriously situation, and an alert 3 is an accident (or inflight fire as I would be inclined to call). An alert 3 calls on community responders to respond to.
This tends to be the trend at the airports. It is about the same as JFK and even at LGB (VFR airport with commercial traffic). I remember one night the approach control called me and said a Gulfstream was having hydraulic issues and had no further information. You know this could be a little thing but could always be huge. I called the major alert. It was very late at night. The whole airport lit up like a Christmas tree with firetrucks and rescue vehicles. I was afraid I was going to get in trouble for over-calling the alert but my supervisor said he was not doubting my call at all. That was good. LOL.