As long as you don't go too far up, you can always try and land on the crane...then drop down to the floors right below the ladders, but don't drop down from the crane all the way to the roof, you will die. It is the concept of fall damage. There used to be a hack (way back in the day) where they would add in the feature known as "No Fall Damage". Unfortunately, those days are long gone and we may never see No Fall Damage again.