WEIRTON, W. Va. — Life in this industrial area has slowed to a shuffle along with the steel mills that used to power it. Young people have moved away, leaving an aging population that no longer has the energy to put on street fairs or holiday parades.

In fact, this community in West Virginia’s northern panhandle holds an unwelcome distinction. With just 71 babies born on average for every 100 residents who die, Brooke County, in which Weirton is partly located, has the largest such gap in the nation among counties in metropolitan areas, save for a handful of places that are magnets for retirees. (Hancock County, which contains the other part of Weirton, is in similar demographic straits.)

The main reason Brooke County is so far off the national number — which is 171 births to 100 deaths — is that it has missed out on one of the dominant demographic trends to emerge from the recent census: the influx of young immigrants into communities across the United States. The median age for Hispanics, by far the largest immigrant group, is just 27, far lower than the median age for whites of 41.

Without immigrants or economic opportunities to keep its younger residents close to home, Brooke County and others like it are showing their age. At St. Paul Catholic Church in Weirton, the Rev. Larry Dorsch has buried 15 people this year and baptized one. The American Legion in Wellsburg has closed because of a lack of young supporters. Volunteer fire departments are so understaffed that people come from other towns to fight fires.