Fire hydrants

There was a thunderstorm followed by a light rain this evening, so after supper Alice wanted to take a walk in the rain.  She loves to wear her rain boots and carry her Thomas umbrella.  As we walked around the block, Alice kept pointing out the fire hydrants, and one time added, "That's where the fire comes out."  It was a logical guess, really, but I explained that only water came out of fire hydrants.