Question:
Some friends of mine recently had the overly exciting experience of a major fire on their corner. (Apparently, some propane tanks blew up in a small ink factory there, and a huge fireball ascended, and it was quite a scene. No fatalities.)

It was an eight alarm fire - but while telling me this tale, the couple had a friendly disagreement about what exacty this means. One thinks that it means that eight companies of the Somerville Fire Dept. were called out; the other thinks that fire departments from a total of eight cities or towns were summoned. They asked me to ask a.f.c.a. to settle the question. I was going to pull out the phone book and find the non-emergency number of the Somerville Fire Dept., but they prefer to take the word of Unca Cece's nieces and nephews.

Answer: An "eight alarm fire" (which would be a BIG fire) means that a total of eight fire companies or stations were called to the scene. It doesn't matter where those companies came from. Many smaller towns or suburbs don't have that many fire companies, so have contract or reciprocal agreements with neighboring cities or towns ("mutual defense treaties", so to speak). Even it a city does have eight (or more) stations, they may not want to send them all to the scene, since that could drastically reduce their ability to respond to other calls. Then, they might call in a company from a neighboring suburb to help out. Also, a station in a neighboring suburb may be much closer to the scene than other companies in the same city.

So basically, both of your friends could be considered correct. Eight companies were called to the scene. Maybe all from the same city, maybe not. I find it odd, though, that your friends would take the word of a bunch of people on the internet, who might just make stuff up as they go along, rather than the word of the actual fire department involved.