How about this: (someone school me where I am wrong and I deserve handicap points for not looking it up!)
The bonding forces of what gets destroyed (rock split/radiator burst/ etc.) is LESS than the bonding forces/ energy of Frozen water which is LESS than the energy in liquid water.
Water is a polar molecule, and as a liquid, has the ability to reorient itself into the most compact package possible (like people packing into a crowded bus). When heat energy is lost, water goes through a phase change into a solid, and those molecules cannot move about as they did before. Frozen, they cannot reorientate themselves to pack themselves as dense around one another... hence, ice expands, and being less dense. floats on liquid water.
As these frozen water molecules take up their new (less compact and more space requiring status), they still have a hell of a lot of strength/energy, which overloads the strength of the copper pipes in your house/ whatever, and they burst...
Does that sound good? I am sure I am misstating something here...This is just a guess on my part