The reflective blue tower of St. Francis Medical Center is the tallest structure in Lynwood, a symbol of the outsized role the hospital plays in the mostly working-class city.  Founded in 1945, the facility delivers about 5,000 babies a year, more than almost any other hospital in the state. It is home to a trauma center, treating gunshot victims and others with serious injuries. And it’s the largest employer in Lynwood, a town of less than five square miles.