This is a common tactic employed by animal rights activists at homes of researchers and other persons involved in animal testing. Break a lower level window, feed in the homeowner’s hose and turn on the water. Not necessarily the perpetrators in this case but these groups are all fellow travelers and share information on tactics and techniques.
Many years ago we heard that neighborhood kids would prank people by turning on their outside faucet and just letting the water run. But there are also cases we know where people have had pipe ruptures or hose ruptures on their washing machines and had the same thing happen.
It would make for a very high water bill aside from any damage done.
So we developed the habit of turning off the water whenever we go away for even overnight.
We also turn off the hot water tank as if that goes dry for some reason, like a leak, and tries to turn on, it can cause a fire.