A few years back my son was pulling a double axle trailer with an industrial vacuum on it. It weighed 10K. the truck was a single cab 3500 Chevy. Two tires on the trailer blew, almost simultaneously, the trailer imbedded itself in to a concrete lane divider, the pintle hitch tore apart, and he ended up flipping several times, and over a steep bank. The truck was about 20' down. He was just bruised up, BTW. Mostly from where the shoulder strap kept him in place as the thing tossed him around like a paint shaker. It took two articulating boom heavy truck wreckers to pull the truck up and back on to the highway. And two rollbacks, to remove the mess.
The towing bill was right at $10,000 USD.