The NY Times reported last week on deaths exceeding births in some U.S. cities, notably Pittsburgh.
Two local friends of mine used to live in Pittsburgh, before emigrating to New York --- where they had a child!
The causes of population decline can frequently be economic in nature, and they probably are in this case. Pittsburgh is not a place where more people die than anywhere else, or where something in the water prevents conception.
Some cities and counties, for example in Florida, deaths exceed births more because of in-migration of the elderly rather than the out-migration of the young.