Alaska has the northernmost and westernmost lighthouses in the United States, and some of the most isolated as well. Keepers at the Cape Sarichef and Scotch Cap Lights on Unimak Island in the Aleutians were not permitted to bring their families to the station, and served four years before getting an entire year of leave; Cape Sarichef received no supplies from August 1912 to June 1913, and both lights shut down in the winter due to sea ice. Scotch Cap was also the site of the worst lighthouse disaster in US history, when it was destroyed by a tsunami in the 1946 Aleutian Islands earthquake, killing all five coastguardmen stationed there.