One time about 20 years ago, I was coming down the mountain I live on in my first piece of equipment, a 10 ton JLG boom truck. As soon as I exited my driveway onto the county road, I eyeballed it as to it's condition. Looked real slick, touched the brakes to confirm, OH YEAH... figured I'd put the chains on before getting to the 12% grade section in the 1600' vertical drive to the valley below. I eased it over to the shoulder, which had enough gravel to roughen at least the right side tires up enough to come to a stop. Then I laid out the left side chains in front of the rear single axle, then the right side, and when I walked back around to the left side prior to getting back in the cab and pulling ahead a few feet (putting the rear outriggers down to lift the rear axle up would have turned it into a big snowboard) my previously laid out left side tire chains were missing. They were sliding down the road, by the time I caught up with them they were 20' ahead of the truck. Once chained up, I drove the 1/2 mile to the scary part, the 12% down grade straightaway for about a half mile. Even chained up, I stayed over on the right shoulder to use the roughness there, too much at one point, and got sucked into the ditch, at about 4 MPH. Long story short, I uncaged the 55' boom, swung it a bit to the uphill side (sucked in of course), enough to get some dunnage under the tires in the ditch, and managed to extricate myself. Calling a tow truck was not an option, maybe the next day but not that day. Even back then I didn't keep my rig on the mountain, but in town, but I just happened to have it up there when the ice storm hit.