Sci-fi film about virtually everyone found dead in a town


I watched a science fiction film on tv many years ago, but I don't remember the title of it.

It was about a group of scientists investigating a town where seemingly everyone in it died for no apparent reason.

The only scene I remember well shows a couple scientists investigating the town where they discover that a baby and an elderly man are the only survivors.

During that scene, after the two of them hear a baby crying, they're briefly disturbed by a helicopter flying overhead and motion for it to fly away so they can hear where the cries are coming from.