More than 3 million homes and businesses are still without power in Florida. It could be a month before the lights are back on in parts of the Florida Keys.
From the air, the search and rescue campaign in response to Hurricane Irma's destruction is vast. On the ground, the effort is about knocking on doors -- where there are doors to knock on.
Fire and rescue teams are walking the debris-filled streets, marking homes that are safe and documenting the damage.
CBS News' Elaine Quijano spoke with Carlos Calvillo, who works with California Task Force 1, which operates under FEMA's direction. The group is comprised of about 80 hazmat specialists, urban search and rescue crews, and doctors.
With the help of K-9 officers, Calvillo's team is looking for survivors.
"If they actually detect human remains, or a live body, we'll be able to come in, then we begin the process of taking the structure apart," Cavillo said. "And in this case, we haven't found anything."
Close to 10,000 residents in the Florida Keys rode out the storm. Twenty-five percent of homes were destroyed while 65 percent sustained damage.
Residents tell Quijano they are preparing, and expecting not to have power for perhaps a month. With no running water and no cell phone service, people in the Keys are facing daunting challenges ahead.
Meanwhile, in Key West, relief arrived in the form of two Chinook helicopters on Wednesday at an empty shopping center parking lot. For some people, it's the first aid they've received since Irma made landfall.
The tarmac at Homestead Air Force Base is a launching point for the relief mission, which now includes all five branches of the U.S. Military.