Icicle

An icicle is a spike of ice formed when water dripping or falling from an object freezes. Typically, icicles will form when ice or snow is melted by either sunlight or some other heat source (such as heat leaking from the interior of a heated building), and the resulting melted water runs off into an area where the ambient temperature is below the freezing point of water (0 °C/32 °F), causing the water to refreeze. Over time continued water runoff will cause the icicle to grow.

Icicles can pose both safety and structural dangers. Icicles that hang from an object may fall and cause injury and/or damage to whoever or whatever is below them. In addition, ice deposits can be heavy. If enough icicles form on an object, the weight of the ice can severely damage the structural integrity of the object and may cause the object to break.

Source: en.wikipedia.org/wiki/Icicle – 30.12.2008