Bloody lucky, or unlucky! Many years ago we were coming across the top of the Butcher Country Track in Vic high country and arrived at the scene of a tree branch that had come down on a guy and his family sheltering from the heat. Luckily, or not, they had yet to get out of the vehicle and it fell right on top of their landy. Main branch that hit the car was about 6" diameter. Funny thing was it must have been a soft landing as it barely made any impact, but by the time we stopped to getting it clear of the roof it took a good hour. This was in the middle of summer, in the middle of the day, not a breath of wind either - weird how the planets align. Glad you weren't hurt.