A fall from greater than 3 times your height is considered to have enough force behind it to fracture a bone. Since the bone cell (matrix) is a solid matter, it is not likely to convert to a liquid state with an acute increase in force (i.e., a fall). Possibly the immersion of the bone in moisture, or low pressure over a long period of time? In any case, a bone will not turn to a liquid state secondary to the impact from an acute blow or fall. It's just not chemically possible. Hope this helps!