A friend mentioned that a major retail chain recently had a small fire break out in their store and that the sprinkler systems activated, torrenting down water across the entire shopping floor.

Imagine that happening while you're shopping. Imagine the water, the panic, the slippery floors. Also, imagine the cleanup job - drying the floors, walls, and fixtures; and then replacing all the stock. It can't be a fun experience for shoppers nor store employees.

I'm however sure you'd agree that all that wetness is far preferable to fire and smoke.