This school fire is a good one — Exira is planning a controlled burn of its original brick building. The AP article about it notes that it was closed not just because of declining enrollment, but because “The structure was starting to shift.”
Schools burned down with some regularity into the beginning of the 20th century — the core 1917 building in Traer replaced one destroyed in a fire. I don’t know when the last major accidental fire in an Iowa school was. The Cass County Courthouse burned down in 1932, one of two courthouse fires in the 20th century according to this list.
UPDATE: Burn has been delayed.