MIAMI (AP) - As South Florida fell under hurricane warnings, gas shortages and gridlock plagued thousands of people fleeing for high ground ahead of Irma.

More than a half-million people have been ordered to evacuate to escape the Category 5 hurricane tracking toward the state, and that volume turned normally simple trips into tests of will.Carmen Pardo and her 6-year-old daughter, Valeria, drove around Miami for seven hours, gas station to gas station, frantically searching for somewhere to fill up the tank to evacuate. They found nothing."She was saying, 'Mommy I'm so tired, I can't do this anymore,'" she said Thursday. "It was craziness."Pardo booked the only flight she could find leaving the city, to Orlando, where she reserved two seats on a bus bound for Tallahassee on Friday."It's the beginning of an adventure," she said.Late Thursday, the National Hurricane Center issued the first hurricane warnings for the Keys and parts of South Florida, including some of the Miami metropolitan area of 6 million people and Lake Okeechobee. It added a storm surge warning and extended watch areas wrapping around the tip of the peninsula.People along the Atlantic coast anxiously watched the behemoth while Irma battered the northern Caribbean, killing at least 11 people and leaving thousands homeless after destroying buildings and uprooting trees.At least 31,000 people fled the Florida Keys, which could begin seeing wind and rain from Irma as early as Friday night, Gov. Rick Scott said. He noted the size of the powerful storm, and told residents not to become complacent."It is wider than our entire state and could cause major and life-threatening impacts from coast to coast. Regardless of which coast you live on, be prepared to evacuate," Scott said. He ordered all public schools, colleges and universities to close Friday through Monday.With winds that peaked at 185 mph (300 kph), Irma has been the most powerful hurricane ever recorded in the Atlantic.NASA secured Kennedy Space Center and SpaceX launched an unmanned rocket for an experimental flight. Kennedy closed its doors to all nonessential staff and a crew of about 120 people will ride out the storm on site.Most of the critical buildings at Kennedy are designed to withstand gusts of up to 135 mph (220 kph). Irma's wind could exceed that if it reaches Cape Canaveral.Georgia Gov. Nathan Deal ordered evacuations for all areas east of Interstate 95, including the city of Savannah, and authorized about 5,000 National Guard members to help with response and recovery. Georgia was last struck by a hurricane of force Category 3 or higher in 1898.Noel Marsden said he, his girlfriend, her son and their dog left Pembroke Pines north of Miami with plans to ride out Irma in Savannah, only to find the city was also shutting down because of Irma. Marsden wasn't sure where they would all end up."I've got a buddy in Atlanta and a buddy in Charlotte. We'll wind up one of those two places because there are not hotels, I can tell you that," he said.Irma's eventual path and Florida's fate depends on when and how sharp the powerful hurricane takes a right turn, National Weather Service Director Louis Uccellini said."It has become more likely that Irma will make landfall in southern Florida as a dangerous major hurricane," the Hurricane Center said in a forecast discussion Thursday afternoon.The last Category 5 storm to hit Florida was Andrew in 1992. Its winds topped 165 mph (265 kph), killing 65 people and inflicting $26 billion in damage. It was at the time the most expensive natural disaster in U.S. history.U.S. Air Force Reserve weather officer Maj. Jeremy DeHart flew through the eye of Irma at 10,000 feet Wednesday and through Hurricane Harvey just before it hit Texas last month.He said Irma's intensity set it apart from other storms."Spectacular is the word that keeps coming to mind. Pictures don't do it justice. Satellite images can't do it justice," DeHart said.---Reeves reported from Ormond Beach, Florida. Associated Press writers Seth Borenstein in Washington; Gary Fineout in Tallahassee and David Fischer in Miami contributed to this report.---HURRICANE NEWSLETTER - Get the best of the AP's all-formats reporting on Irma and Harvey in your inbox:

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