With communication cut to some of the Florida Keys, many are holding their breath for what daylight might reveal.
Storm has lashed Florida since Sunday, severely damaging houses and key crops in the state.
The Virgin Group founder survived the disaster by taking shelter in his wine cellar when the hurricane hit his private island.
Seawater penetrated as much as half a kilometre (one-third of a mile) inland in places.
It comes after two MPs criticised the government's response to the disaster.
Around 5.6 million of Florida's residents have been told to evacuate as the hurricane approaches
Government under cross-bench pressure to justify slow response to catastrophe that has battered the Caribbean.
Malkit Sidhu and her brother Surjit Badesha are accused of masterminding the murder of Jaswinder Sidhu, Malkit's daughter.
US Geological Survey says earthquake hit off Chiapas state near the Guatemalan border with a magnitude of 8.1
Irma's winds of around 175mph (290kph) tore down trees, and flattened homes, schools and hotels, destroying some of the world's most exclusive tourist resorts.
8.1 magnitude quake rocks swathes of the central American country as tsunami warnings issued.