1933 - Witch Shoal Light, Magog, Quebec, Canada - destroyed by Ice Pressure.

The wooden lighthouse here was destroyed in April 1933 as a result of pressure from the ice caused by the rising level of the lake. The aid was rebuilt in 1960 as a small metal tower, which was in turn swept away by spring ice in 1978. Since 1980, the mast that replaced it is left in place only from May to October each year. The aid is owned by the Coast Guard and maintained by a private contractor.
http://www.lighthousedepot.com/database/uniquelighthouse.cfm?value=2635