He was using an RTI ramp. RTI is Ramp Travel Index. It measures the flexibility in a vehicles suspension. Basically you drive up the ramp until any one tire leaves the ground. Obviously in the stiff ass, not much suspension travel hummer, he got a tire way off the gound. His mistake was then trying to set it back down on that tire instead of leaving well enough alone. Now he's got to explain to his family (which looks to be riding in the thing) and his insurance why his $100k Hummer was totalled and rolled in a parking lot.