Florida power company says restoration 'will take weeks' after Irma

— -- After Hurricane Irma made landfall on Florida's west coast Sunday afternoon, an executive from Florida Power & Light estimated that it could "take weeks" to restore power to some parts of the state.

Over 6.5 million accounts were without power in Florida as of Monday afternoon -- a number that represents more than half of the state's residents, according to the Florida Division of Emergency Management -- after the storm's 100-plus mph winds toppled power lines and sheared structures in the state.

"What we think we'll see on the west coast is a wholesale rebuild of our electric grid," Robert Gould, Florida Power & Light's vice president and chief communications officer, told ABC News. "That will take weeks."

"This thing is a monster," he added.

Gould estimated that FPL positioned "17,000 restoration workers from about 30 states" in anticipation of repair efforts before the storm arrived, but said that flooding from storm surges and traffic congestion as residents return home this week would delay the project.

"This is going to be a very, very lengthy restoration, arguably the most lengthy restoration and most complex in U.S. history," he said, asking that customers be patient.

On the east coast of the state, which avoided a direct hit from the eye of the storm, Gould expects repairs to last "probably a week or more."

The storm was losing strength Monday evening, with sustained winds of 45 mph as it approached Atlanta. About 1 million customers in Georgia and South Carolina were without power as of Monday afternoon as well.