Staff evacuated Belize's Half Moon Caye Natural Monument in September 2010 as Tropical Storm Matthew closed in. When they returned on Sept. 30, they found the island's 190-year-old lighthouse had fallen into a heap of rubble at the edge of the sea. Since the lighthouse had been taken out of use in 1997, erosion had moved the water closer and closer to it. The storm was the last blow.
A similar fate threatens lighthouses around the world. People have built lighthouses since the ancient Egyptians erected one on the island of Pharos at Alexandria around 285 B.C. One of the Seven Wonders of the Ancient World, that lighthouse is gone, probably toppled by an earthquake.
The first lighthouse in the United States, in Massachusetts' Boston Harbor, went up in 1716. The British destroyed it 60 years later during the American Revolution.
Lighthouses have been made of wood, stone, concrete, brick, cast iron and steel. Some include living quarters for the keepers. However, GPS, radio and other modern communications have rendered most of the world's lighthouses obsolete. Those still in use have been automated; many have been decommissioned.
When a lighthouse is deemed unnecessary, the agency responsible for it often can't justify money for upkeep. Most lighthouses fall victim to neglect and erosion related to the sea and weather. Sometimes, people realize their value and try to preserve them. Often, as in the case of Half Moon Caye, they're too late.
This list of endangered lighthouses, drawn up with the guidance of Russ Rowlett of the University of North Carolina at Chapel Hill, includes 10 that are seriously threatened, but could be saved with prompt action.