Live: CBS News Miami coverage of Hurricane Ian

ST. PETERSBURG — Hurricane Ian rapidly intensified as it neared landfall along Florida's southwest coast Wednesday morning, gaining top winds of 155 mph, just shy of the most dangerous Category 5 status. 

Damaging winds and rain lashed the state, and forecasters said the heavily populated Fort Myers area could be inundated by a storm surge of up to 18 feet.

Air Force hurricane hunters confirmed Ian gained strength over warm Gulf of Mexico water after battering Cuba, bringing down the country's electricity grid and leaving the entire island without power. Ian was centered about 65 miles (105 kilometers) west-southwest of Naples at 7 a.m., swirling toward the coast at 10 mph.

"This is going to be a nasty nasty day, two days," Florida Gov. Ron DeSantis said early Wednesday, stressing that people in Ian's path along the coast should rush to the safest possible shelter and stay there.