When I was growing up all of the Catholic churches in my hometown and the grammar schools attached to them were stuffed to the gills. In my grammar school (St. Mary's) there were two classes for each grade level, and each one had over 50 students. Now they have consolidated all of the grammar schools into one, and they're going to close some of the churches, too. One interesting aspect of this is that's it's not caused by a decline in overall population -- it's about the same as it was when I was growing up. What has changed is the composition of that population, with non-Catholic ethnic groups making up more of the population. But I'm sure that part of the cause is still a decline in church attendance. The school consolidation was probably the result of general population trends, especially once the baby boomers passed through the system.