At the time of the 1900 storm the highest point in the city of Galveston was only 8.7 feet (2.7 m) above sea level. The hurricane brought with it a storm surge of over 15 feet (4.6 m), which washed over the entire island. The surge knocked buildings off their foundations and the surf pounded them to pieces. Over 3,600 homes were destroyed and a wall of debris faced the ocean. The few buildings which survived, mostly solidly built mansions and houses along the Strand District, are today maintained as tourist attractions.

The highest measured wind speed was 100 miles per hour (160 km/h) just after 6 p.m., but the Weather Bureau's anemometer was blown off the building shortly after that measurement was recorded. The eye passed over the city around 8 p.m. Maximum winds were estimated at 120 mph (190 km/h) at the time, though later estimates placed the hurricane at the higher Category 4 classification on the Saffir–Simpson Hurricane Scale. The lowest recorded barometric pressure was 28.48 inHg (964.4 hPa), considered at the time to be so low as to be obviously in error. Modern estimates later placed the storm's central pressure at 27.49 inHg (930.9 hPa), but this was subsequently adjusted to the storm's official lowest measured central pressure of 27.63 inHg (935.7 hPa).

As severe as the damage to the city's buildings was, the human toll was even greater. Because of the destruction of the bridges to the mainland and the telegraph lines, no word of the city's destruction was able to reach the mainland. At 11 a.m. on September 9, one of the few ships at the Galveston wharfs to survive the storm, the Pherabe, arrived in Texas City on the western side of Galveston Bay. It carried six messengers from the city. When they reached the telegraph office in Houston at 3 a.m. on September 10, a short message was sent to Texas Governor Joseph D. Sayers and U.S. President William McKinley: "I have been deputized by the mayor and Citizen's Committee of Galveston to inform you that the city of Galveston is in ruins." The messengers reported an estimated five hundred dead; this was considered to be an exaggeration at the time.

The citizens of Houston knew a powerful storm had blown through and had made ready to provide assistance. Workers set out by rail and ship for the island almost immediately. Rescuers arrived to find the city completely destroyed. It is believed 8,000 people—20% of the island's population—had lost their lives. Estimates range from 6,000 to 12,000. Most had drowned or been crushed as the waves pounded the debris that had been their homes hours earlier. Many survived the storm itself but died after several days being trapped under the wreckage of the city, with rescuers unable to reach them. The rescuers could hear the screams of the survivors as they walked on the debris trying to rescue those they could. A further 30,000 were left homeless.

The dead bodies were so numerous that burying all of them was impossible. The dead were initially weighted down on barges and dumped at sea, but when the gulf currents washed many of the bodies back onto the beach, a new solution was needed. Funeral pyres were set up on the beaches, or wherever dead bodies were found, and burned day and night for several weeks after the storm. The authorities passed out free whiskey to sustain the distraught men conscripted for the gruesome work of collecting and burning the dead. More people were killed in this single storm than the total of those killed in all the tropical cyclones that have struck the United States since. This count is greater than 300 cyclones, as of 2009. The Galveston Hurricane of 1900 remains the deadliest natural disaster in U.S. history.

Hurricane Harvey is expected to make landfall on the upper Texas coast Friday night, bringing “life-threatening and devastating” flooding, according to US government warnings. Mandatory evacuation notices have already been issued to residents of several counties.

US president Donald Trump and vice president Mike Pence are warning Texans to be prepared. “Remember to #planahead!” Trump tweeted, with a video of him striding through the offices of the Federal Emergency Management Agency (FEMA), which handles the US’s natural disasters, then seated at a long table talking to officials. Pence retweeted the message, adding that those in the path of the hurricane should check the National Weather Service’s Twitter feed.

The Trump White House has not done much to prepare for the storm, however. Two of the three politically appointed positions in the over-9,000-employee FEMA have yet to be filled by Trump appointees; the same goes with the top position at the National Oceanic and Atmospheric Administration, which monitors storms. Even the Department of Homeland Security, which oversees both agencies, doesn’t have a permanent secretary, after John F. Kelly left to become White House chief of staff on July 31.

Trump did make nominees to the two empty top FEMA jobs, deputy administrator and deputy administrator for protection and national preparedness, on July 19. Presidential nominees need to be confirmed by the Senate, however, and that was just before the Senate’s August recess. Instead holdovers from Barack Obama’s presidency, David Grant, and Kathleen Fox, are holding the jobs.

“Federal civilian employees with decades of experience are currently serving as acting in those positions,” a FEMA spokesperson said. “Throughout the transition to the new administration, FEMA has ensured that career civilian staff are in place in key positions throughout the agency.”

Few places are more in harm’s way of Hurricane Harvey than Rockport, a town of less than 10,000 people and about 30 miles up the Texas coast from Corpus Christi.

That Harvey presents a life-or-death situation was emphasized in clear terms by Rockport’s mayor pro tem on Friday.

His warning: If you stay to face Harvey, prepare to die.

“All the advice we can give is get out. Get out now,” Mayor Pro Tem Patrick Rios told South Texas TV station KIII-TV. “Those that are going to stay, it’s unfortunate but they should make some type of preparations. Mark their arm with a Sharpie pen. Put their Social Security number on it and their name.”

If his message wasn’t clear enough, he added, “We’ve got first responders available, but once it gets bad, we are not going to put their lives in jeopardy. They will not get help we will not be dispatching folks that decided to stay.”