Oh dear, I just don't believe, IMO, that a lost dog roaming around will be "OK".
Have the vets and humane societies in the area been checked recently? Are there posters up for this dog?
These sorts of things happen so quickly, and unfortunatley there is no "Undo" button. I think it is easy to get complacent in our lives. We get use to routine and every once in a while things just happen. So sad.