Six days after Hurricane Michael stormed through the Florida Panhandle, roads remain impassable, washed out and unsafe in many parts of the region, and officials are warning that the recovery could be long and expensive.

Across the northwest Florida coast, from Panama City to Mexico Beach and Apalachicola, debris is being cleared, but many residential streets remain impassable because of fallen trees and wires. In other places, roadways are destroyed. Emergency crews were being mobilized to rebuild guardrails and traffic signal systems and repair other damage caused by the historic storm.

The conditions are so dire, local officials worry that residents desperate for food and water can’t get to aid stations, grocery stores and the few gas stations that are open.

“We are working on the crews to clear every one of the streets to make sure that there’s availability for you to get out of your home and be able to navigate to the aid stations that we have across the city,” Panama City Manager Mark McQueen told residents in a Facebook Live message Sunday.

While there was still no official assessment Monday of the damage to roads and bridges in Michael’s aftermath, there were reports of a collapsed bridge in Mexico Beach, blown-off highway signs and widespread problems with a vast majority of traffic signals, many so severely damaged they will need to be rebuilt.

Michael made landfall last Wednesday as a Category 4 storm, devastating parts of Florida, Georgia, North Carolina and Virginia. The storm has killed at least 18 people, a number that officials say is likely to rise as emergency personnel continue search-and-rescue operations in the hardest-hit areas.

The storm’s powerful eyewall swept north-northeast — still as a Category 3 storm — hitting one of the poorest swaths of Florida, Alabama and Georgia.

It wiped out entire blocks, including houses and shopping centers, and knocked down hundreds of thousands of trees and power lines. Roadways were left covered with debris, glass from broken windows, power lines and flipped vehicles.

The storm will go down in history as one of the strongest to hit the continental United States. At landfall, its 155-mph peak winds ranked fourth-highest on record, according to The Washington Post’s Capital Weather Gang.

Gas was in short supply and most stations remained shuttered Monday; many roads were closed, and detours were in place from Panama City to Mexico Beach and Apalachiola. Where roads were open, drivers were urged to watch out for downed power lines and trees.

National highways are largely open, with the exception of US 98, which follows the coastline along the Panhandle and is closed in multiple locations because of washouts. There is no estimated time for its reopening.

In Panama City, one of the hardest-hit areas, McQueen said the goal is to get all the debris off the roads, but officials asked for patience because the cleanup effort could take weeks.

State officials said fuel shortages are not widespread, but in some communities residents were running out of fuel, scrambling to find where it was available and waiting in line for hours once they did find it. Most gas stations in the hardest-hit areas sustained damage or were completely destroyed, and without electricity, those still standing are unable to operate.

Florida has made first-responder fueling depots available to utility crews across the Panhandle, Gov. Rick Scott (R) said, to ensure that utility trucks have the fuel they need to get the power back faster. Scott said 500,000 gallons of fuel is being distributed daily at 40 fueling stations to support restoration efforts.

Tolls remain suspended in northwest Florida, including at Mid-Bay Bridge and Spence Parkway in Okaloosa County, Garcon Point Bridge in Santa Rosa County, Bob Sikes Toll Bridge in Escambia County, and Orchard Pond Parkway in Leon County.

Since Thursday, 17,000 utility workers have arrived in the region to rebuild and repair crippled infrastructure, along with 2,000 cellphone company workers and 18,000 search-and-rescue personnel, joining 4,000 Florida National Guard troops and multitudes of police officers and firefighters. Florida Highway Patrol troopers and Florida Forest Service crews were on the ground Monday in Bay, Gulf, Franklin, Jackson, Calhoun, Leon, Liberty and Gadsden counties, clearing roads and cutting trees.