The Enriquillo-Plantain Garden fault runs along southern Haiti, part of the boundary where the Caribbean tectonic plate grinds eastward against the North American plate at roughly 20 millimeters per year. For two and a half centuries, this fault had not produced a major earthquake. Stress accumulated invisibly, stored in rock, until it released all at once as a magnitude 7.0 event centered just 25 kilometers west of Port-au-Prince. The shaking registered intensity IX on the Modified Mercalli scale in the capital and its suburbs -- violent enough to topple well-built structures, let alone the buildings of a country with no building codes. The quake was felt across the Caribbean: in Cuba, Jamaica, Venezuela, Puerto Rico, and the Dominican Republic. But nowhere did it hit harder than in the densely built, inadequately constructed neighborhoods of Port-au-Prince.

Haiti had no building codes. Engineers would later note that few structures in Port-au-Prince could have withstood any significant seismic event. Buildings rose wherever they could fit -- on slopes, on land their occupants did not own, with walls of unreinforced concrete and minimal steel. An estimated two million Haitians were squatters, living in structures built cheaply and quickly on marginal ground. When the shaking began, these buildings did not sway or crack; they simply fell. The three Doctors Without Borders medical facilities in Port-au-Prince were all damaged, one completely destroyed. The country's primary nursing school was leveled. The main prison collapsed. Government officials found themselves working from police headquarters near the airport, their offices and records gone. Several parliamentarians were trapped in the ruins of the Presidential Palace. In the heat and humidity, bodies buried in rubble began to decompose within hours.

How many people died remains contested to this day. The Haitian government put the toll at 316,000. The Inter-American Development Bank estimated between 200,000 and 250,000, calling it "the most destructive event a country has ever experienced when measured in terms of the number of people killed as a share of the country's population." A later investigation by Radio Netherlands suggested the figure was closer to 92,000. An unpublished USAID-commissioned survey placed it between 46,000 and 85,000. The true number may never be known. What is certain is that Port-au-Prince's morgues were overwhelmed within hours. Government crews collected thousands of bodies by truck and buried them in mass graves. The International Red Cross estimated that three million people -- nearly a third of Haiti's population -- were affected. At least 85 United Nations personnel were killed, including the head of the UN mission, Hedi Annabi, and his deputy.

In the immediate aftermath, survivors dug through rubble with their hands. The first international rescue team to arrive was Iceland's ICE-SAR, landing within 24 hours. The Dominican Republic, sharing the island of Hispaniola, was first to provide aid, opening its hospitals and airports to support operations. But the scale of destruction overwhelmed every effort. The airport's air traffic control tower was damaged, creating bottlenecks that delayed incoming flights. Roads were blocked with debris. Communication networks were down. Doctors Without Borders, running short of medical supplies, fashioned splints from cardboard and reused latex gloves. Hospitals performed amputations without adequate anesthesia. Over 3,000 patients were treated by MSF in the first week alone. The confusion over authority -- who was coordinating, who was in charge -- compounded the chaos. The Haitian government eventually handed control of the airport to the United States to speed the flow of relief flights.

Presidents Obama, Clinton, and Bush coordinated American fundraising efforts. The European Union pledged 330 million euros. Brazil committed 375 million reais. Nations around the world opened their wallets. But rebuilding a country that had been impoverished long before the earthquake proved vastly more difficult than the initial rescue. Haiti's history of national debt, exploitative trade policies imposed by foreign powers, and repeated foreign intervention had created the very conditions -- the poverty, the unregulated construction, the fragile institutions -- that turned a natural event into an unnatural catastrophe. Years later, much of the promised aid had not materialized or had been absorbed by administrative costs. The earthquake did not just destroy buildings. It exposed, with brutal clarity, the consequences of centuries of systemic neglect.