Hurricane Michael, blamed for more than 30 deaths and for causing up to $10 billion in insured losses, evidently also was a disaster for Florida Panhandle beaches.

The U.S. Geological Survey still is assessing the damage, but its preliminary assessments show a dramatic loss of beachfront at Mexico Beach, where Michael made landfall around 1 p.m. Oct. 10 with peak winds of 155 mph.

The dunes in a 30-mile stretch from the splendidly white sands of St. Andrews State Park, in Panama City, to Mexico Beach "appear to have undergone overwash,"  Kara Doran, the agency's Coastal Change Hazards team leader, said in the preliminary report.

Given the fact that the beaches were under attack from elevated water levels for a number of tide cycles, the protective dunes might have been wiped out  even before Michael made landfall, which would have worsened erosion and damage to the infrastructure.

USGS said that along with the U.S. Army Corps of Engineer it plans to conduct data-collection flights to get a handle on just how much sand was lost and how vulnerable the beaches might be for the next storm.