Don't understand why sprinklers in buildings seem to have stopped. Seem to remember years ago everyplace had them?
Sprinklers spraying water everywhere aren't the best idea in car parks or places with liquid fuel all over the place.
- If there is already a pool of burning fuel then water sprinklers can cause a pool of burning fuel to be carried to other places e.g. underneath other cars that aren't yet alight;
- Water droplets tend to be heavy enough to drop through the surface of the burning fuel where they get heated up and then turn rapidly to steam from underneath the burning fuel; causing the burning fuel to "explode", and the fire spread further.
In aircraft hangars for example they use foam based fire suppression so I guess car parks could use that, but it's a lot more expensive than just running water pipes and fitting automatic sprinkler heads every few metres, so they don't.