Shepard Smith described the devastation Florida could experience if Hurricane Irma stays on its projected course.
The entire state of Florida could be hit hard, the host warned.
"If it happens the way they believe it's going to happen ... this will decimate south Florida," he told viewers.
The most likely track of the storm is that it will hit Key Largo and hit water again north of the West Palm Beaches. For southern Florida the projected path is the "worst case scenario."
Irma's 175 mph winds will hit tall buildings as if they were 200 mph, Smith warned. The tops of tall buildings in Miami would be destroyed.
"There's no hurricane rating for buildings at 200 miles an hour, not 30 stories up," he said.
The southeast beaches will be 10 to 15 feet underwater, Smith predicted.
"This is as serious a storm in the 30 years that I've been doing this as anyone has ever covered."