What contributes to extinguishing room fires faster?
Many people have debated regarding what SPECIAL value affects extinguishing fires. This inconclusive discussion implies that Intelligence affects the rate a fire is extinguished. Apparently, the only factor that might affect extinguishing fires is the room size. Obviously, smaller rooms are easier and faster to extinguish, especially if it's loaded to capacity with dwellers. Endurance combined with level also helps in these disasters; your dwellers will last longer while putting ones out.
Room level is also a factor I had a maxed out 3 wide living quarters catch fire and it took almost a whole minute to put it out. But disasters in my level 1 3 wide hospital are handle almost instantly. (My dwellers have very strong guns there.) even when I replaced two high intelligence dwellers for two nitwits things were still just as fast.