From The New York Times: Shane Schumerth, a Spanish teacher who had been fired earlier in the day from The Episcopal School of Jacksonville, Fla., returned, pulled an AK-47 assault rifle from a guitar case and killed head of school Dale Regan and himself. In the aftermath, no one has been able to explain Schumerth's violent actions.
Earlier....from CBS News: A man who was fired from a private school in Jacksonville, Fla., returned to campus with a gun and shot the headmistress to death before committing suicide. No students were injured. Officers responded to the Episcopal School of Jacksonville after receiving reports of a person with a gun, and the school was placed on lockdown. When officers arrived, Dale Regan, head of the school, and the gunman were found dead. The gunman has not been identified. Episcopal has about 900 students in grades 6 to 12.