We had this local crazy lady in the town I lived in as a kid, she wasn't homeless but I think like half of her house burnt down but she was still just squatting in it. Turns out she was a paramedic, took a call to a car crash and it turned out it was her whole family and they all died in the crash. I guess finding that scene with all her loved ones made her snap. I always felt super bad for her after I found that out.