From Wikipedia: In recent years the school community has been rocked by a scandal involving a relationship between a teacher and a pupil. It involved the head of music and drama within the school, Bryan Marshall and Jacqueline Livingston, a pupil at the school whom he did not teach. He was sacked at the end of the 2005/2006 term due to this incident.
He always claimed they did not have sex whilst she was at school or underage (under 16) but it's alleged he drove her to a public park during one lunchtime so they could fuck. He is still with her, after leaving his wife.
Otherwise, various counts of alcoholism but I think many teachers got a second chance.