SAN FRANCISCO - The number of suicidal children in San Francisco has hit a record high and health experts say it is clear that keeping public schools closed “is catalyzing a mental health crisis among school-aged children,” according to a lawsuit the city filed Thursday to push its school district to reopen classrooms. San Francisco City Attorney Dennis Herrera announced last week he was taking the dramatic step of suing the city’s own school district, which has kept its classrooms closed nearly a year. In the motion filed Thursday in San Francisco Superior Court, Herrera included alarming testimony from hospitals...