A teenage boy shot dead two staff members and injured two other people, including a student, at a school in northeast Brazil on Tuesday, prompting panicked students to try to escape over a wall, authorities and a witness said. A 13-year-old boy was arrested over the attack at Sao Jose Institute in Rio Branco, the capital of Acre state, the local government said in a statement. Eduardo Rodrigues Cavalcante, who works as a receptionist at a hotel next to the school, said that when the shooting...