Hey - you can bet you won't be the only one who saw him on his route,
for sure. Dogs on the loose can be very hard to catch like that, I've
tried on more than one occasion. Only succeeded once. He may well have
wandered into a yard or other place where there are other kind humans to
help him, especially if anyone else saw the broken string on his collar?
don't beat yourself up - you tried to help but you can't outrun a fit
puppy now can you? (can you?!) He may be safe indoors by now - once he
got hungry maybe someone could catch him more easily.

You're not alone. But at least you're one of the people who try to help
whenever they can! The more people like you there are, the more there
are of the ones that get helped.

Deb.

Can you put food out and a blanketed box in case he is around?

You've got purrs coming.  Chances are he found a place or his people found
him.  Hopefully they aren't abusing him.  He was obviously friendly towards
you so it doesn't sound like they were training him to be a mean dog.

Jill

Please don't beat yourself up - you did the very best you could!
We are sending best wishes for the puppy to have already found his
onetruehome and lots of gentle hugs and purrs for you, Theresa,