I have finally decided on what my collapsed tower used to house:
Many people don’t know that before Voltaire became famous as an author, he owned a very profitable chain of Magic Shops in Mordheim. Until, of course, the comet killed all within the city. Fortunately for Voltaire (and literature), he was spending the new year with his family in a neighboring village when Mordheim was destroyed. This tower used to be Voltaire’s research tower where he developed many of his magic potions. This is also where he gained his first love of writing.