They look innocuous but they can be deadly. Water dripping off a roof can produce icicles weighting multiple tens of pounds quickly, these items falling can do serious damage to a human.

Damage and injuries caused by icicles

Icicles can pose both safety and structural dangers.[5] 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.

The story of an English youth who was killed by a falling icicle in 1776 has been often recounted.[6][7][8][9]

Armstrong, the scientist from the National Snow and Ice Data Center, told a journalist, “Another twist is very large icicles falling from cliffs along highways hitting cars. Where I used to work doing avalanche hazard assessment and forecasting along U.S. Highway 550 in southwestern Colorado, icicles have fallen and destroyed passing cars.”[1]

In 2010, five people were killed and 150 injured by icicles in Saint Petersburg, Russia after a heavy snow that also caused apartment block roofs to collapse, as well as creating water damage to private homes and to the National Library of Russia.[10]

Kathleen F. Jones of the U.S. Army Cold Regions Research and Engineering Laboratory states, “The combination of the ice load and the wind on ice load can break wires, cross arms, and poles and/or other supporting structures. Damage associated with icicles on roofs may be to vehicles parked next to the overhang. Icicles on roofs are also often associated with ice dams that may cause water to infiltrate under the shingles with possible water damage to the house or building and its contents.”

Today in history: January 8th 1887
Wolf Mountain Montana sees the last battle between Crazy Horse and the United States Army