From 1975 to 1979, millions of Cambodian families were murdered, starved, or displaced by the Khmer Rouge regime. The filmmaker Kalyanee Mam’s family was among those uprooted from their homeland. Recently, Mam traveled back to the country from which her family fled. “What I found there shocked me completely,” she told me.

Decades following the dissolution of the regime, thousands of Cambodian families are experiencing a new wave of displacement. By talking with locals on the island of Koh Sralau, Mam found out that since 2007, the government of Cambodia has granted several private companies concessions to mine the country’s coastal mangrove forests. Each year, millions of metric tons of Cambodian sand are shipped to Singapore to expand that island nation’s landmass; Singapore has imported more than 80 million tons of sand so far. According to Mam, “The people and all the living creatures that depend on these forests for their livelihood are forced to cope with this massive loss.” In addition to displacing those who live and work on that land, Cambodia is also destroying its only natural barrier against erosion, rising sea levels, tsunamis, and hurricanes.

A young Cambodian islander, Phalla Vy, has dedicated herself to monitoring and speaking out against the sand dredging. Mam’s exquisite short documentary, Lost World, co-produced by Emergence Magazine and Go Project Films, evokes the pain of losing one’s land—and way of life—through Vy’s eyes.

“Never before have I witnessed the uprooting and displacement of land itself,” Mam said. She wanted to understand where all this sand was going, and how a country—considered one of the most affluent in the world—could destroy someone else's home to build its own. “It is already enough to be removed from one’s land,” Mam said. “It is another thing entirely to have one’s land removed as well.”

Lost World juxtaposes imagery of Cambodia’s vast mangrove forests with footage of sand being deposited in Singapore. At the end of the film, Vy visits Singapore for the first time, where she observes citizens enjoying a brand-new theme park that was built on the land of her people. Throughout the film, her deep indignation is palpable.

“I observed firsthand what happens when the foundation of a community falls apart,” Mam said. “First the land gives way; then the people; and soon, the entire fabric of a culture and identity is lost.”

After Mam and Vy visited Singapore, the filmmaker was struck by the irony of the situation: Singapore’s quest to become one of the greenest cities in the world has led the country to commit what Mam calls “an ecological massacre.”

“Many Singaporeans are not aware of this,” Mam said, “just as many Americans have no idea about the ground we are standing on, what blood has been spilled on this ground, and what lives have been taken to make it possible for us to be here.”