This article was originally published by Hakai Magazine. Before the sea started taking house-size bites out of Nyangai, this small tropical island off the coast of Sierra Leone hummed with activity. I first visited in 2013 while documenting the construction of a school on a neighboring island. It was a cloudless day in April. A group of teenagers was busy setting up a sound system for a party. Old men chatted and smoked in the shade of palm trees. Children chased one another through the maze of sandy lanes while a constant traffic of roughly hewn wooden boats plied the surrounding waters. The silhouettes of coconut palms and June plum trees dominated the island’s profile, and beneath them stood clusters of neat mud-and-thatch homes. The beach that ringed the island was so white, it hurt the eyes, the water a limpid green. I couldn’t stay for long, but Nyangai left a deep impression. In December of the following year, I caught another glimpse of the island, this time while flying over it in a United …