Locked-Up Life Preserver
The last thing you expect is to fall in if you’re going on a nice casual walk along the river. It does happen, and when it does, you hope there’s a life preserver available.
What if a burglar, but the individuals who work in the region could not secure it? You’ll just have to hope that someone noticed you fall in and is willing to help you. People like stealing stuff like this, yes, but it’s hazardous.