FORT LAUDERDALE, Fla. — As Hurricane Irma’s winds, thunderstorms and tornadoes swept through South Florida, more than 2 million homes and businesses had lost power by early Sunday afternoon, the electric utility said.

With Irma moving slowly toward the Gulf coast, a spokesman for Florida Power & Light made it clear that restoration of power would be slow to develop and lengthy.

“Plan for extended and prolonged outages,” FPL spokesman Rob Gould said at a news conference. “We expect, given the fact the storm has slowed down, many of our customers will be out for a day or longer, given that, much like emergency responders, our crews cannot get out and work. It’s just too dangerous.”

Higher winds, heavy rain and storm were expected Sunday. FPL said it had 16,000 crews from around the country – from California, Massachusetts Texas, Colorado and Wisconsin – and its own workers to restore power once hurricane and tropical winds subsided.

That’s about 1,000 more crews than assembled for Hurricane Matthew in 2016. But this will be a much more difficult and widespread restoration, Gould said.

“This will no doubt be one of the most complex, not just in our company’s history but in the history of this country, in terms of restoration,” he said.

“A storm of this magnitude and this intensity will require us in many cases to completely rebuild our electric system, particularly on the west coast.”

FPL said Saturday that it shut down one of Turkey Point’s two nuclear reactors near Homestead. As Irma’s path changed, the decision was made to leave the second reactor online, as hurricane-force winds were no longer expected at the site.

“Our nuclear plants are absolutely safe. One of our units is shut down. The other is running fine,” Gould said.

The same applied to the utility’s nuclear plant in Jensen Beach.

“It is not expected that the St. Lucie nuclear power plant will be shut down as result of Irma, though we will closely monitor the changing weather conditions,” the utility said.

FPL Saturday lowered the number of homes and businesses it expects to lose power to 3.1 million customer accounts, or 6 million people in its service area, which is half the state. On Friday, the utility had estimated that 4.1 million accounts or 9 million people would lose power in the storm.