The first predictions were that Hurricane Irma would hit Miami square-on. But the storm changed course early in the weekend: It is now clear that Tampa Bay, on Florida’s Western Gulf Coast, was going be the major city hit hardest as the storm sweeps the state on Sunday.

Tampa and the surrounding area, whose population is about 4 million, is not prepared for a storm of this magnitude. Too many homes and businesses are too close to the water, and coastal defenses are too few, for catastrophic damage to be avoided.

“The metropolitan area is the most vulnerable in the United States to flooding and damage if a major hurricane ever scores a direct hit,” Darryl Fears wrote in a richly reported Washington Post piece published in late July — a piece that terrifyingly anticipates the exact scenario the city may be about to experience.

Fears explains that, in 2010, Tampa’s regional planning council conducted a study on what would happen if a Category 5 hurricane, with winds around 156 mph, hit the area. This hypothetical hurricane, called Phoenix in the report, is a bit stronger than Irma was when it hit the Florida Keys (as a Category 4 with 130 mph winds).

The anticipated effects of a powerful hurricane hitting Tampa, as detailed by the report, are horrifying. You can read the full thing here, but here’s Fears’s summary of its conclusions:

The fictitious Phoenix hurricane scenario projects that wind damage would destroy nearly half a million homes and businesses. About 2 million residents would require medical treatment, and the estimated death toll, more than 2,000, would top the number of people who perished from Hurricane Katrina in Louisiana and Mississippi. Florida’s most densely populated county, Pinellas, could be sliced in half by a wave of water. The low-lying county of about a million is growing so fast that there’s no land left to develop, and main roads and an interstate connecting it to Tampa get clogged with traffic even on a clear day.

This scenario remains within the realm of possibility. A 2013 World Bank study ranked cities according to their vulnerability to major storms. Tampa ranked number seven — not among American cities, but among all cities in the world.

So Irma’s move away from Miami, which itself is poorly prepared to handle flooding, hasn’t proven to be much of a blessing. Tampa is incredibly vulnerable — and has been less of a focus for preparations, since Irma’s worst effects were expected to be felt elsewhere in the state.

This storm is very, very scary.