If you don't help in time, don't show sympathy later.
If a person is troubled in front of you and God made you worthy that you can help him, even then you are just watching like a spectacle by hiding in the crowd of the world, then please do not show sympathy later. Many times it happens that we are not able to help even if we want to, which may be due to some compulsion. But what if someone doesn't help just because the same person is either not related to us or we don't want to get involved in matters of others. Sometimes we or other people's silence only encourages evils in the world and we see it as mere spectators.Try not to be an audience, but to be helpful, at least make an effort, maybe one of your initiatives can encourage other people as well and soon you will see a crowd gather who is against the wrong thing.
Or if you are not able to do this then please do not go to the victim or the sad person later and say do not worry, we are with you, because the truth is that you were never with them and never will be, so don't give false hopes.