The Luverne elementary-middle school was evacuated yesterday afternoon after teargas was accidentally released. Superintendent Al Carr says the building was evacuated around 1 p-m after staff members noticed the smell of ammonia in the office. Carr says an old safe in the office contained several vials of ammonia teargas designed to keep away burglars if the safe was ever illegally opened. A couple of the vials apparently fell and broke open. Students, who were kept out of the building for about half an hour, were let back in after the ammonia was cleared away.