Highland High school was closed on Monday and Superintendent Chris Armstrong says it was because of a failed circulating pump in their heating system. He says because the pump wasn’t circulating hot water in the system it caused freezing pipes in one of the classrooms which caused some leakage. Armstrong says they had the pump fixed by noon on Monday and then were able to fix water damage in the classroom that received the most damage. He says they don’t know why the pump broke, and noted that it was only about 10 years old.