Simplify the following text for a Grade 10 native English-speaking person.
Original: The building 's plans were drawn in the early 1960s , before student activism prompted a concern for safety , but the Fleming Building 's narrow windows , all located above the first floor , and fortress-like exterior led to a campus rumor that it was designed to be riot-proof .
Simplified: The building 's plans were drawn in the early 1960s , before student activism created a concern for safety . Nevertheless , the Fleming Building 's narrow windows , all located above the first floor , and castle-like outside led to a campus rumor that it was made to be riot-proof .