I understand your indecision completely; to make things more difficult, we all know most of the time if you approach someone about something like this, they are likely to get defensive; but then you wonder if they might be the few people that would appreciate you checking
My example :
On my walking route, I had seen an older looking dog on the road a few times. One day I saw the dog again and I saw a man working in his driveway. I stopped and asked the man if he knew who owned the dog. Eventually it came out that he owned the dog, his response "people don't usually drive down this road very fast". I tactfully mentioned that I had worked at an animal emergency hospital and had seen dogs hit by a car, so I was worried (and refrained from saying "it only takes once"), and he was still defensive. You'd think that someone might appreciate that
I've also alerted my neighbor to his dog being out and running loose (when we saw her she was standing in the turning/exit lane next to a 4 lane street looking up at us in the window), to which I got a half-hearted thanks (as in, being polite

)
If you think you're unlikely to run into these people, I'd say its worthwhile asking them whats going on

I can only please one person per day. Today is not your day, tomorrow doesn't look good either.
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"You didn't know of the magical powers of the break stick? It's up there with genies and Harry Potter as far as magic levels go." SisMorphine 01/07/07