I once woke up in the middle of the night to the sound of metal banging against a wall. Someone was yelling, but, in my half-asleep state, I waved it off as an unruly neighbor returning drunk from a party. When the noise didn’t stop, I listened closer. “Help!” he was yelling. My neighbor who uses a wheelchair had fallen. I got up and called 911 for him. That was perhaps the only time I was thankful for the thin walls of my condo building.