I grew up in this neighborhood in the 1970s, and plenty of hot-shot weekend warrior pilots would buzz the area at well below 400 feet AGL. It was a matter of time before someone crashed on the Hillside. It got to be a real problem, with neighbors calling the FAA with tail numbers, and a few brandishing shotguns. Not everyone, not every day, but often enough that it became a topic of neighborhood conversation. It's way to early to know what the cause was of this crash, but my money is on someone getting too sporty with their plane and losing control.