1780 was among the worst years in history for North Atlantic hurricanes. The season kicked off in mid-June when a squall formed in the Caribbean and tore across St. Lucia and Puerto Rico. In August, two more storms struck the Caribbean islands and New Orleans, killing dozens of people and wrecking all the ships moored in the mouth of the Mississippi River. The month of September was relatively quiet, but October 3 brought the infamous Savanna-la-Mar hurricane, which drowned the coast of Jamaica in a deadly storm surge. “The sky on a sudden became very much overcast, and an uncommon elevation of the sea immediately followed,” British Colonel John Dalling later wrote. “Whilst the unhappy settlers…were observing this extraordinary phenomenon, the sea broke suddenly in upon the town, and on its retreat swept everything away with it, so as not to leave the smallest vestige of Man, Beast or House behind.”

While the Caribbean was still reeling from the effects of the Savanna-la-Mar storm, the behemoth that would become known as the “Great Hurricane” was brewing thousands of miles away in the Atlantic. Meteorologists are uncertain of its exact birthplace, but most believe it formed off the coast of West Africa near the Cape Verde Islands. The slow-moving storm system then migrated west, feeding off the warm waters near the equator and growing in size and strength. By October 9, it was looming just off the coast of Barbados and the other islands of the Lesser Antilles.

Since the Great Hurricane came long before the advent of modern storm tracking, the residents of the Caribbean had no warning of what was about to hit them. In Barbados, witnesses noted that October 9 was a particularly pleasant day, distinguished only by a brilliant blood-red sky in the evening. A light rain began to fall after sunset and continued throughout the night, giving way to downpours and gusting winds by midmorning. By nightfall on October 10, the entire island was in the grip of punishing winds typical of a category-five hurricane. Houses creaked, swayed and then blew apart, and trees and shrubs were uprooted and thrown about like kindling. Many of the ships docked in the island’s harbors were swept out to sea or dashed against the shore. Witnesses later noted that the gales ripped the bark off felled trees—a phenomenon believed to occur only when winds climb above 200 miles per hour.

“The very tone or sound of the wind was wound up to a pitch almost bordering upon a whistle,” British colonist William Senhouse later wrote. “Rain fell like a deluge, which added great weight to the wind and when driven in our faces felt like hail or small shot; the thunder and lighting was tremendous and incessant.” In the capital city of Bridgetown, Governor James Cuninghame was forced to retreat to a basement cellar after the wind ripped his house’s roof away. When the cellar flooded, he and his family fled outside and passed an anxious night hiding under a cannon, terrified that at any moment it might blow over and crush them.

The Great Hurricane ravaged Barbados for most of late October 10 and early October 11. Sugar cane fields were flattened, and nearly all of the island’s buildings—including those made of stone—were blown away like houses of cards, leaving only pockmarked foundations behind. The island’s forts and military garrison were leveled, and one cannon was picked up and carried hundreds of feet by the wind. Many residents were buried beneath the rubble of their collapsed houses. Others were struck by flying debris or drowned when the rivers and streams flooded. “The most beautiful island in the world has the appearance of a country laid waste by fire, and sword,” British Admiral Sir George Rodney later wrote.

Some 4,500 people lay dead on Barbados, but the island was only the first target in the Great Hurricane’s crosshairs. On October 11, the storm turned northwest and passed over the island of Saint Vincent, where it ripped apart over 500 houses. Nearby Saint Lucia was hit even harder. The hurricane pulverized the island for several hours, flooding its harbors and tossing one helpless ship on top of a hospital. In Port Castries, only two houses were left standing. Next to feel the storm’s wrath was Martinique, where screaming winds and a 25-foot storm surge claimed 9,000 lives and leveled a cathedral and a brand-new hospital.

The destruction wasn’t limited to land. The storm came during the height of the American Revolution when the French and Spanish were fighting a naval war against Britain for domination of the Caribbean islands. Both sides saw dozens of warships overwhelmed before they could escape to calmer seas. British Admiral Rodney lost several vessels at St. Lucia, and a Dutch flotilla of 19 ships sank after being thrown onto rocky shoals near Grenada. An even more horrific scene unfolded off the coast of Martinique, where the storm enveloped a 40-ship fleet of French supply ships. Nearly all the vessels were driven to the ocean floor or thrashed against the coastline, killing some 4,000 sailors.

After leveling Martinique, the Great Hurricane continued to drift north across the islands of Dominica, Guadeloupe and St. Kitts. At the Dutch colony of Saint Eustatius, a colossal sea surge killed an estimated 4,000 people. The storm then clipped Puerto Rico and Hispaniola on its way north toward the open ocean. It finally died down after reaching the chilly waters of the North Atlantic sometime after October 18, but not before striking tiny Bermuda, where it caused mass devastation and wrecked several dozen ships.

The Great Hurricane left much of the eastern Caribbean in utter ruin. The misery only mounted in mid-October, when another massive hurricane struck a Spanish fleet in the Gulf of Mexico and caused 2,000 fatalities. The storms crippled the Caribbean’s sugar trade, and despite an outpouring of charitable donations and government aid from Britain and elsewhere, it took several years before many of the islands recovered. “The melancholy appearance of every person and thing, struck me with a degree of terror not easily to be described,” wrote a British colonist who arrived in Barbados in early 1781.

All told, an estimated 22,000 people lost their lives during the Great Hurricane of 1780. Because of the outbreaks of famine that followed—particularly among the islands’ slave population—some historians place the number closer to 30,000. To this day, it remains the deadliest Atlantic storm in recorded history.