By the time meteorologist Isaac Cline warned his fellow citizens, it was too late.

On this day in 1900, a hurricane made landfall in the island city of Galveston, Texas. Galveston was a rich port city, but it was less than 10 feet above sea level, and it wasn’t prepared for a hurricane. In fact, Cline, who was the city’s connection to the national weather services, had publicly stated that a hurricane would never make landfall in Galveston as part of a campaign against building a seawall to protect the city. Sadly, according to the federal government, at least 8,000 people were killed in the natural disaster, which remains the deadliest in American history.

“Now rated a Category 4 tropical storm on the Saffir-Simpson Scale, the Great Galveston Hurricane occurred at a time when tropical storms weren’t named and the National Hurricane Center (NHC) did not yet exist,” writes Steve Melito for On This Day in Engineering History. But the United States Weather Services Bureau, which was established in the 1800s, maintained a local office where Cline worked.

The meteorologist, who also lived in Galveston with his wife and three daughters, was the city’s only frontline weather advisor. “Galvestonians had been aware of the storm since September 4, when it was reported moving northward over Cuba,” writes the Texas State Historical Association. “From the first, however, details had been sketchy because of poor communications.” The local residents had few incoming reports of the storm, as ships out at sea had no ability to communicate with the land and telegraph lines elsewhere were downed by the storm.

Because of the lack of communication, the historical association writes, the city’s 38,000 inhabitants were unaware the hurricane was heading for Galveston. Rain and wind were the only warnings. “Not even an encroaching tide disturbed them greatly,” the association writes. “Galvestonians had become used to occasional ‘overflows’ when high water swept beachfronts. Houses and stores were elevated as a safeguard.”

Cline, however, thought a hurricane was coming. According to National Oceanic and Atmospheric Administration, on the morning of September 8, “Cline said he harnessed his horse to a cart, drove to the beach, and warned everyone of the impending danger from the storm–advising them to get to higher ground immediately.”

But his warnings had little effect on either Galveston locals or the tourists who flocked to the island’s miles of beaches in the warm months, writes History.com. Given that the island was completely overwhelmed by the hurricane, likely the only safe answer would have been to evacuate everyone via the bridges that connected Galveston to the mainland. Some people did take this route, the historical association writes, but not enough.

“Houses near the beach began falling first,” the historical association writes. “The storm lifted debris from one row of buildings and hurled it against the next row until eventually two-thirds of the city, then the fourth largest in Texas, had been destroyed.” Cline and his brother Joseph Cline kept sending reports to the national weather offices until the telegraph lines went down, NOAA writes.

A massive wave, caused by the hurricane, buried the city under 15 feet of water, which receded, leaving ruins and a death toll of more than 8,000 people, according to NOAA. Among the dead was Cline’s wife, although his three daughters survived the storm. Images from Galveston’s public library show the destruction that came in the storm’s wake and the grisly task of retrieving and laying to rest thousands of bodies.

“Although Galveston was rebuilt, it never reestablished itself as the major port of call it once was,” NOAA writes. “The city was soon overshadowed by Houston, some miles inland and connected to the Gulf of Mexico by a canal.”