But a few of the usual places were open.
At Mangrove’s Mike, a popular diner with a dolphin sculpture at the entrance, many locals, fishermen and the few tourists packed the place for a hearty breakfast.
The restaurant always closes at 2 p.m., which is just about the time tropical force winds are expected to begin hitting the keys. The storm is expected to make landfall in the Keys between 4 and 6 p.m., earlier than was previously forecast.
While the hurricane flags were flying at the Coast Guard station in Islamorada, the latest forecast says there is only a 10 percent chance the storm will reach enough intensity to become a hurricane when it hits the island chain.
In anticipation of what could be the first hurricane strike Florida has seen in seven years, residents and government officials began preparing for Isaac on Saturday.
Miami-Dade and Broward counties ordered schools closed Monday, and private schools and universities followed the lead. Monroe County ordered schools closed through Tuesday. All three counties also opened shelters and urged residents to stay indoors until the storm passes sometime Monday morning.
Mass transit also is scheduled to shut down Sunday across South Florida.
Miami-Dade buses, Metromover and Metrorail will stop service at noon, and Broward County Transit and Tri-Rail have suspended bus service for the day.
Port Miami closed at 11 p.m. Saturday, and Port Everglades in Broward remains closed to waterside and landside operations, except for limited .
Major airports remained open early Sunday, but nearly 550 flights were canceled at Miami International Airport as of 11 a.m. Sunday, and Fort Lauderdale-Hollywood International Airport reported 135 flights canceled since Friday.
Tolls were lifted on Card Sound Road’s northbound lanes leaving the Keys on Sunday morning, though authorities are advising visitors and residents to remain indoors and ride out the storm.
In Miami Beach, at least 1,200 homes lost cable and internet service beginning at about 8:30 a.m., according to Atlantic Broadband representatives.
Florida Gov. Rick Scott has issued a state of emergency, expressing concern about the damage Isaac might do once it passes the Keys and fuels up in the warm Gulf of Mexico. It was forecast to grow into a Category 2 Hurricane with 100 mph winds as it approaches the Panhandle.
“The issue in the Panhandle is flooding,’’ said Scott, who noted that the region is still saturated from Tropical Storm Debby, which the region with rain in June.
Scott said he cleared his calendar through Tuesday, and will be in Tampa only on Sunday.
“We may need to help out other states,’’ he said.
Scott said he spoke with Republican presidential candidate Mitt Romney twice on Saturday. They talked about safety, emergency management measures and the situation in Tampa, he said.
Rick Knabb, director of the National Hurricane Center in West Miami-Dade, said that a strengthening Isaac in the Gulf could pose a storm surge threat to Tampa Bay, where the Republican National Convention was scheduled to convene Monday in an area vulnerable to flooding. Events will now be delayed until Tuesday afternoon.
In Miami-Dade, officials also issued an evacuation order for people living in mobile homes, unsafe buildings and homes in low-lying, flood-prone areas. The Keys did the same, adding an order for boat dwellers to seek safer shelter.