Why does density of water get smaller when it turns into ice?

Question

Although densities of liquids get higher when they become solid, density of water diminishes when it becomes solid.

Answer 1

Because the molicules move apart from eachother.
The Ice expands.

Answer 2

Because the VOLUME of the water expands by 11%. So the same amount, or quantity of water, is then occupying a larger space, and is thereby "spread out"--meaning less density. This is why icebergs float with about 90% of the berg below the surface, but only about 9% above the surface of the surrounding water.

Answer 3

Generally, water expands when it freezes because of its molecular structure, in tandem with the unusual elasticity of the hydrogen bond and the particular lowest energy hexagonal crystal conformation that it adopts under standard conditions. That is, when water cools, it tries to stack in a crystalline lattice configuration that stretches the rotational and vibrational components of the bond, so that the effect is that each molecule of water is pushed further from each of its neighboring molecules. This effectively reduces the density ρ of water when ice is formed under standard conditions.
(quoted from: http://en.wikipedia.org/wiki/Water_(molecule)#Density_of_water_and_ice )