MIAMI, Fla. (AP) — As the devastated Florida Keys began reopening to residents who fled Hurricane Irma, officials warned the returning islanders to bring enough supplies to sustain them for a while, because no one yet knows when water and power will be fully restored.

“The Keys are not what you left several days ago when you evacuated. Electricity, sewer and water are intermittent at best,” said Monroe County Mayor George Neugent during a news conference Saturday.

Officials opened up U.S. 1 on Saturday all the way south to Marathon for residents, business owners, disaster workers and supply trucks. They also announced plans to let the same groups have access all the way to Key West starting at 7 a.m. Sunday.

Recovery efforts are well underway with the Salvation Army planning to serve 5,000 barbecue dinners Saturday night in Marathon and Key West, marking the first hot meals for many since Irma made landfall nearly a week ago.

Roads were being cleared and recovery centers are being set up in the area to help residents fill out FEMA, insurance and small business relief paperwork. Even Publix was open until 5 p.m. on Friday.

Officials had agonized over the decision to reopen the islands, knowing residents were desperate to assess the damage with their own eyes, yet worried about harsh living conditions for those who choose return.

Curfews remained in effect and returning residents received a clear message from Keys officials — you must be self-sufficient. They encouraged residents to bring tents, small air conditioning units, food, water and medications.

Officials said their detailed hurricane plan didn’t account for some unique challenges brought by Irma, which nearly wiped out parts of the middle Keys, while Key West remained in decent shape.

Getting Key West residents and businesses owners to the southernmost point remained a challenge as authorities work to keep out tourists, gawkers, looters and others who could hamper recovery efforts.

Nearly two dozen checkpoints in the hardest hit areas will be heavily staffed with law-enforcement officers to check IDs to ensure only authorized residents and relief workers get through.

Meanwhile, officials said they hope to open government offices, courts and schools in the Keys on September 28.