Trundling in climbing and land management is the releasing of loose rocks to reduce the possibility of future rock falls. It’s often done by excavation crews or other professionals, and is not something that should ever be done by amateurs. In cases where it’s done improperly, trundling can be very dangerous, with the falling rocks potentially damaging property or hitting people.
In the following video, a group of people manage to release a decent sized boulder from the side of a steep hill. Falling uncontrolled, the boulder begins to head towards the direction of a truck parked below. Fortunately a larger rock is able to stop the boulder’s descent.
If that rock wasn’t there to stop the fall and the boulder managed to hit the truck, it seems likely that the vehicle would have suffered an immense amount of damage. The owner is certainly lucky it stopped. Let this be a reminder to leave rocks alone unless you truly know what you’re doing and no for a fact that there’s nothing below.