Hurricane Irma shocked the country this week with images of wind and water that haven’t been seen in some time along the hurricane-wary coastlines of the United States. Although people in those regions always have preparation for these storms somewhere in their minds, the two Florida Power & Light (FPL) nuclear plants—both of which powered through the hurricane—had both a background of design and preparedness to stand on as well as some recent, last-minute preparations.

According to Florida Power & Light, both of its nuclear plants (two units at St. Lucie, and two units at the Turkey Point power station) have been constructed 20 feet above sea level, in order to protect them against the dual threats of floods and storm surges. The plants have been designed for the rugged environment sometimes occurring along the hurricane coast and, according to FPL, the two plants “have been specifically built to withstand natural disasters such as hurricanes, tornadoes, earthquakes, and tidal surges.”