St. Mary Parish, which bucked a two-decade trend with a population increase before the 2010 Census, is losing people again. The U.S. Census Bureau’s yearly estimates say the parish’s population in July 2017 was 50,973, down nearly 7 percent from the 2010 Census. That’s a loss of more than 3,600 people in seven years. The parish’s biggest cities, Morgan City and Franklin, took the biggest hits, both with decreases of more than 9 percent. Berwick, which in 2010 stood 54 people short of the 5,000-resident threshold that turns a Louisiana town into a city, has lost 361 people, according to the estimates. Population ...