And the pain was felt far away as well: in Jacksonville, where there was still major flooding from epic storm surge, heavy rains and rising tides; in Georgia, where at least 1.2 million customers were without power Tuesday; and in Charleston, S.C., where Irma’s effects coincided with high tide, causing some of the worst flooding since Hurricane Hugo, which devastated the area in 1989.
The political will Mr. Wolshon cited has arisen, in large part, from the two defining, and very different, disasters of the century: the Sept. 11, 2001, terrorist attacks, and, four years later, Hurricane Katrina, whose floodwaters put most of New Orleans underwater and left more than 1,800 people dead.
The terrorist attacks in New York and Pennsylvania revolutionized the way American government coordinated disaster response. Katrina stimulated a new and robust conversation about the power of natural disasters, and, more specifically, forced Americans to rethink the growing threats from floodwater.
These issues have become central themes for government in recent years, and Richard Serino, a former deputy administrator of the Federal Emergency Management Agency, said he was not surprised that the response to the storms thus far has gone relatively well.
“It’s no accident,” he said. “We’ve been training people for this for the last 16 years.”
These events, and other disasters before and after, have fed into the collective knowledge of how a modern nation should respond to hurricanes, serving as catalysts for improvements in weather forecasting, evacuation policies and hurricane-resistant building practices.
Experts said all of them most likely played a role in keeping the death tolls lower than expected in the last few weeks. The planning and response also benefited from a few lucky turns in the weather, the growing sophistication of personal technology — the iPhone did not exist when Katrina struck — and a public dialed in to the internet and tuned into 24-hour television news.
The deadly problems posed by hurricanes are at once ancient and rather new: Hal Needham, a coastal hazard scientist who runs a private consulting business in Galveston, Tex., notes that it was not until after World War II that populations began to soar in the hurricane-vulnerable states of Texas and Florida. The rise of satellite-based meteorology came only in the 1960s. Before that, hurricanes could still come as a surprise.
Today, lawmakers enjoy better weather forecasts, but now face the problem of what to do with millions of people who may lie in a storm’s path. Mr. Wolshon does not agree with all of the evacuation decisions made in the face of Harvey and Irma, but he said they were made with an evolving and increasingly sophisticated understanding of the challenges.
In Houston, Mayor Sylvester Turner and other local officials decided not to call for a mandatory evacuation before the arrival of Harvey, in part because of the nature of the threat to the area. Harvey, by the time it reached Houston, was not expected to bring storm surge or high winds, so much as pounding, extended rains. In this case, it was difficult to know which areas would flood and which would not. So officials decided to encourage people to stay put.
It was a marked difference to the strategy of Gov. Rick Scott of Florida, who announced Thursday to 6.5 million people: “Leave now, don’t wait.”
Dr. Needham said that the move was probably the right one. “When Irma was bearing down on Southeast Florida it did appear several days out that we could potentially see Category 5 winds in the metro Miami area,” he said. “When you have a massive flood event, if you can you just go up, if you’re in a condo or an apartment.”
But in whipping, hurricane-force winds, sheltering in place probably would not have been as safe as hitting the road. Evacuation also made sense given the threat of huge storm surges, experts said.
Miami did not end up experiencing extreme winds, though much of South Florida did take a beating. Lives may have been saved because of the drastic overhaul of South Florida building codes after Hurricane Andrew in 1992. That massive storm damaged or destroyed 125,000 homes in the area, and the new codes have forced developers to build structures that could better withstand hurricane-force winds.
Houston, too, has learned from its tragic past. In July 2001, southeast Texas was hit hard by Tropical Storm Allison, which caused serious flooding. It prompted officials at Houston’s Texas Medical Center, billed as the largest medical complex in the world, to undertake a $50 million upgrade that included installing flood doors and putting generators high enough that they could not be inundated.
Dr. Needham said that these changes probably helped keep the death toll down in Texas. “If the power goes out in a hospital with premature babies and elderly people on ventilators, you can really see an increase in the loss of life,” he said.
Both Texas and Florida probably also benefited from the growth and sophistication of the federal Department of Homeland Security, and the training that even tiny communities have undergone since the Sept. 11 attacks.
The storms also unfolded at a time when government disaster response has grown more sophisticated, an evolutionary process that did not necessarily begin with the Sept. 11 attacks: James Witt, the FEMA director under President Bill Clinton, recalls going to Congress to fund a modern operations center after discovering what passed for one at FEMA headquarters up to that point.
“The operations center was so bad that they had telephone wires hanging out of the ceiling and foldup chairs and tables,” he said.
But the federal disaster-response system grew markedly after 9/11. And while the Homeland Security Department has been criticized as being expensive and bloated, it has also insured a system in which local, state and federal officials are inured to the idea of working and communicating together.
Still, few observers were openly celebrating the government response to the storms in the United States. The damage was too vast, not just in Texas and Florida but also in Puerto Rico and the U.S. Virgin Islands. The response continues, with the rebuilding likely to last years. And everyone knows that Texas and Florida had some good fortune beyond the scope of human influence: The big winds never hit the major urban areas, and in Florida, capricious Irma did not deliver a storm surge as devastating as some had predicted.
“While thankfully the impact on people injured or killed was low, this is largely a factor of luck,” said Ahmad Wani, chief executive of One Concern, a California-based company that seeks to use new technologies to create “next-generation disaster response” systems.
Mr. Serino said that Harvey had introduced another cutting-edge idea: relying on residents, not just government workers, to make significant contributions to hurricane response. “Now we’ve seen images of neighbors helping neighbors,” he said. “They’re the real emergency medical workers.”