Amid Hurricane Milton’s devastation, a sliver of good news
Cellphone data suggest evacuation mandates, warning systems worked
Earlier this month Hurricane Milton caused an estimated $50 billion in damage and claimed the lives of at least 14 people, yet didn’t deliver the scale of destruction some had feared.
Preparedness seems to have played a role in Milton’s relatively low death toll, according to a panel recently hosted by Harvard’s Salata Institute for Climate and Sustainability. This is “good news” according to Satchit Balsari, co-director of the research platform CrisisReady, which uses cellphone data to study the travel patterns of people in disaster zones.
“Warning systems and evacuations and people getting used to those risks and hardening their homes actually make a difference,” said Balsari, associate professor in emergency medicine at Harvard Medical School and Beth Israel Deaconess Medical Center. “Evacuation hit 80 percent to 90 percent in some of the key areas.”
Those key areas, concentrated mostly along Florida’s coast, are “mandatory evacuation” zones. Further inland, he said, evacuation rates dropped to around 45 to 50 percent. “So yes, while we’re celebrating that mandates work, about half the population had not evacuated.”
He added that people with pets, elderly residents, or residents living in fortified buildings were likelier to stay put. Another factor in evacuation rate, according to Balsari: whether a population has experienced a disaster in living memory. As recently as 2022, Florida was struck by the deadly Category 4 storm Hurricane Ian.
“The storm dropped only 10 inches of rain in western North Carolina, but there are over 250 people dead. They weren’t expecting flooding there.”
Daniel Schrag
Balsari also pointed to the Bangladesh cyclones of 1990 and 1994.
“What’s interesting is they were almost the same storm. They had almost the same track, same intensity, made landfall in the same place. In 1990 the cyclone hit in Bangladesh, and 138,000 people died. Three years later, the same storm hits, 350 people died.”
The difference he said, was that by 1994 the government had invested in an early warning system and constructed concrete bunkers across the country where people could ride out the storm.
“Something like 450,000 people sheltered in those bunkers,” Balsari said. “And 350 people died.”
Hurricane Helene, a Category 4 storm which hit the South just weeks before Milton, is tied to more than 200 deaths, with economic losses estimated at $250 billion.
“The storm dropped only 10 inches of rain in western North Carolina, but there are over 250 people dead, still, I think, about 100 missing, and hundreds and hundreds of homes destroyed,” said Daniel Schrag, the Sturgis Hooper Professor of Geology and professor of environmental science and engineering. “They weren’t expecting flooding there. In North Carolina, they weren’t expecting the kind of impacts from the storm.”
Referring to Milton, Balsari added: “A lot of people who died in this hurricane died not because of the hurricane, but because of tornadoes that were spawned by the hurricane.
“So that’s an interesting phenomenon. And it suggests it’s the surprise element [that’s deadly].”
However, no matter how prepared a locale is, there are some things you cannot anticipate. Balsari pointed to an epinephrine shortage in the wake of Hurricane Helene.
“The storm just unleashed tons of bees, and they have such a huge spike in bee stings that a lot of the relief organizations are actually trying to get more epinephrine to North Carolina as soon as possible.”
Balsari cautioned that we’re only starting to understand the full toll of Hurricanes Milton and Helene.
“You lose cellphone coverage, power is lost at home, your nebulizer is not going to work, you cannot refrigerate your insulin, and access to dialysis centers are sometimes interrupted. In the couple of months after a hurricane, people continue to die at a higher rate than expected.”