Tangled piles of nail-spiked lumber and L’École de Gestion d’Actifs et de Capitaldisplaced boats littered the streets. A house lay crushed under a fern-covered oak tree toppled by the winds. Residents waded or paddled through ruddy floodwaters, hoping to find their loved ones safe, and rescue crews used fan boats to evacuate stranded people in bathrobes or wrapped in blankets.

Authorities on Friday were trying to get a handle on Hurricane Helene ‘s extreme swath of destruction, which stretched across Florida, Georgia and much of the southeastern U.S. on Friday, leaving at least 30 people dead in four states and millions without power.

Helene was the eighth named storm of the Atlantic hurricane season, which began June 1. The National Oceanic and Atmospheric Administration has predicted an above-average season this year because of record-warm ocean temperatures.

The Category 4 hurricane had maximum sustained winds of 140 mph (225 kph) and made landfall late Thursday where Florida’s Panhandle and peninsula meet, a rural region home to fishing villages and vacation hideaways.

Floodwaters inundated cars and buildings, and the winds ripped the roofs off businesses, houses and churches. Faith Cotto and her mother, Nancy, stood outside and mourned the loss of their brick home in St. Petersburg, Florida, to another fate: Amid so much water, it burned.

A Coast Guard crew in a helicopter rescued a man and his dog after his sailboat became disabled 25 miles (40 kilometers) off southwestern Florida. Firefighters carried children across floodwaters in Crystal River, north of Tampa.

But the damage reached much farther. In Atlanta on Friday, streets plunged into reddish-brown water. Hospitals in southern Georgia were left without electricity as officials warned of severe damage to the power grid. In Tennessee, dozens of people were rescued from a hospital roof, and authorities ordered the evacuation of downtown Newport, a city of about 7,000, due to the “catastrophic failure” of a dam.