While smoke detectors are key in alerting occupants of fire, they are also a reactive form of fire protection, and can only save those who are able to react. Fire sprinklers, on the other hand are proactive, providing firefighters the time they need to extinguish the fire and help avoid potential tragedies and severe structural damage.
http://www.nj.com/south-jersey-voices/index.ssf/2013/03/letter_fire_sprinklers_can_mak.html
