Why do we have a fire alarm but no fire department?

The fire alarm triggers the fire prevention system so sprinklers go off. It also alerts sims so they can use the extinguisher quicker. Firefighters never once worked for me in sims 3 always showing up hours after the fire either started or was put out so imo theyre unneeded. Ive had many fires in game and with or without the alarm I could always get them put out with at most 3 destroyed/charred items.

Edit: wow didnt realize how old this post was