All Los Angeles Unified School District schools have been ordered closed Tuesday due to an unspecified “credible threat” of violence to students at numerous schools in the sprawling district, and a schools official confirmed that it was a bomb threat to the school district. Los Angeles Unified is the nation’s second-largest school district, with more than 900 campuses and more than 640,000 students. Ramon Cortines, the school system’s superintendent, said the threat was against students at multiple schools. LAUSD spokeswoman Monica Carazo confirmed that it was a bomb threat. “It was not to one school, two schools or three schools, it was many schools, not specifically identified, but there were many schools,” Cortines said. “That’s the reason that I took the action that I did”/Washington Post. More here.