My parents had come to visit me in London, and had rented the loft in Putney for a week.
Within 10 minutes, my Dad had fallen on the floor because of a broken chair (that had been left there by the previous tenant in hope nobody would notice) and hit his head. From that moment, my parents just kept discovering new problems: the window pane was broken, with a big glass shard sticking out of the window (dangerous, and windy), a couple of light bulbs were not working, the bed was unstable (another fall!). Not to mention the bathroom: bad smell, and there were problems of water drainage).
They were really disappointed!