I do some commercial mowing so I get into some spots that I am not familiar with. I was mowing a subdivision that has several undeveloped lots, some with a slope that kept me from mowing across the lot and forced me to go up and down. In the middle of one lot was a drainage ditch about 4-5 feet wide that ran all the way to the bottom of the lot and emptied into a catch basin. It ranged from 3 feet deep to nearly level with the surrounding ground. I was backing around the top of the ditch while maneuvering around a power pole when the edge of the ditch collapsed. I stabbed at the brake to stop the tractor and access the situation. I was backing, so I was twisted in the seat, this helped to let my heel hit the hydro pedal at the same time as the brake. This shot the tractor forward over the edge of the ditch. The front end of the tractor fell into the drainage ditch which was filled with football sized stones a couple feet below. It hit hard. I managed to lift the front end back to level with the loader and some rocks. I locked the rear end and backed up until my front end cleared the ditch.Everything seemed to be alright at the time. I counted myself very lucky, it could have went much worse. I just wish I had gotten everything checked out after the first repair, but I was getting behind on jobs and was eager to get back to work.This proves that even a tractor as tough as the Bobcat can be damaged. I guess a little time and a lot of money and everything will be just fine.