The Keys are cut off from the mainland, as the 42 bridges that link them are being assessed for damage. On Monday morning, almost 60 percent of the state woke up without power and saw Irma had flooded the streets, toppled trees and left tons of debris.
Irma hit Florida on Sunday morning as a risky Category 4 storm, the second highest level on the five-step Saffir-Simpson scale.
"We don't have a comprehensive insight into what the damage is", Bryan Koon, Florida director of Emergency Management said late Sunday.
"This is a city that, for whatever reason, dodged a bullet", Buckhorn said. "I don't have any numbers on fatalities at this point".
The full breadth of the damage remains unclear, particularly in the hard-hit Keys, where communications and travel were still hard.
"The greatest impacts from Irma will be felt with winds increasing to 40 to 50 miles per hour with gusts near 70 miles per hour along and east of the center of the storm track by early this afternoon". The officials also instructed residents to beware of downed power lines. Although downtown Fort Lauderdale was spared major damage, trees were uprooted throughout the area.
On the Atlantic coast off South Carolina, Hilton Head Island's 42,000 residents were under an evacuation order this morning.
Irma has left around 6.5 million people in Florida without power, and killed at least 8 people in southeastern states.
Winds were so strong in Miami that at least three construction cranes crashed into buildings.
Night-time curfews have been imposed in areas such as Miami, where 13 people were arrested on suspicion of looting.