I've been in one industrial fire where the sprinklers went off.
I was supervising a maintenance crew doing a repair. A welding torch
threw a spark and started some dust going. The fire watch hit it
immediately with the small hose but that seemed to make it worse. I
was standing about 20 feet back, and the main fire hose was 20 feet
I turned and ran for the fire hose, and the fire went past me on the
way. Holy Crap! I dropped the fire hose and booked for the exit.
About then the sprinklers activated. It got dark and foggy and I
whacked my shin really good on a piece of equipment.
Anyway, the sprinklers saved the plant and 144 jobs, in a rural
Southern town where there were no other jobs and never would be. We
had some water damage and we chased shorts in the machinery for about
a year, but we were running, filling orders, and paying wages.
That made me a believer. I'm not 100% sure I would have made it out
at all if the sprinklers hadn't held the fire back.