Birley Academy, in Birley Lane, Sheffield is under lockdown this morning after an incident in which three people were injured. A boy, 17, has been arrested on suspicion of attempted murder after an incident in which three people were injured. Moments ago (around 11:10am), pupils were allowed to leave the school. Subscribe to The Star’s free newsletter One mum said "It's been very calm and orderly. I'm very pleased with the school. "[My daughter] said it was really calm. They were in their... Read this story