About 15 seconds into the video below, you might wonder aloud “Why is the truck driver accelerating before the crane has even been secured to the trailer?” The thing is, these guys didn’t even get a chance to secure the crane in the first place.

In another instance of heavy things on inclines illustrating the power of gravity, the wheels on the trailer begin to turn soon after the crane rolls onto the trailer. Not long after, the weight of the crane begins to push the semi down the incline despite the tractor’s back wheels being in the air while its bumper scrapes against the ground. Check  out the video below.