PANAMA CITY, Fla. (AP) - Thousands of National Guard troops, law enforcement officers and medical teams are working their way into damaged communities to search for survivors of Hurricane Michael.

  

What authorities don't want are evacuees trying to come back to check on their properties. Bay County Sheriff Tommy Ford says residents aren't being allowed past checkpoints until crews clean up downed power lines and trees.

  

Florida emergency officials say the devastation is so massive that it remains unclear if people who ignored evacuation orders were killed.

  

Authorities said that 285 people in Mexico Beach refused to leave, and many homes in that community were washed away. A National Guard team found 20 survivors there overnight and more crews were working through the wreckage on Thursday.

  

Hospitals and nursing homes are so damaged in the Panama City area that ambulances and helicopters are being used to ferry patients elsewhere.

  

Michael remained a hurricane for 12 hours and 200 miles as it moved over Florida and Georgia, and other teams are looking at reports of possible tornado damage well inland.