Many Floridians race to outrun Irma as others hunker down

Miami prepares for Irma

Last Updated Sep 7, 2017 9:49 PM EDT

It's a race to outrun Hurricane Irma, the most powerful hurricane ever recorded in the Atlantic. The fury of the Category 5 storm was seen in the Caribbean, where at least 10 people were killed.

In Florida, more than half a million people live in mandatory evacuation zones. People along the Georgia coast have also been ordered to evacuate.

Irma is expected to reach Florida by Sunday morning, and is currently traveling with sustained winds of 175 mph, according to the National Hurricane Center. 

Miami Beach, which is just a few feet above sea level, floods often in minor storms. The area's most sought-after sand sat in a parking lot on Thursday. Families were able to fill 10 sandbags a piece to protect their home against Irma. A line of cars a quarter-mile long waited for their chance to shovel.

"It's going to be terrifying," said 16-year-old Diego Oropeza. "We've been watching the news all along and we think this is a big deal." 

Families were able to fill 10 sandbags in preparation for Hurricane Irma.  CBS News

In Miami-Dade County, 650,000 people were under a mandatory evacuation order Thursday evening, CBS News correspondent Mark Strassmann reports.

Gridlock gripped I-95 all the way to Orlando.

By one estimate, nearly 40 percent of gas stations in Miami and Ft. Lauderdale have run dry. Cases of water were also running low. 

"Coming out of the Southeast, especially, it's a pretty bad scenario for Miami-Dade County," Miami-Dade Mayor Carlos Giminez said.

Ahead of Irma arriving in Florida, Gov. Rick Scott announced Thursday that he's directing all K-12 public schools, state colleges and universities and state offices to close beginning Friday until Monday.

"Floridians are facing a life-threatening storm in Hurricane Irma, and every family must prepare to evacuate," Gov. Scott's statement read. "Our state's public schools serve a vital role in our communities as shelters for displaced residents and staging areas for hurricane recovery efforts. Closing public schools, state colleges, state universities and state offices will provide local and state emergency officials the flexibility necessary to support shelter and emergency response efforts."

Irma is bigger and more powerful than Hurricane Andrew, which killed 61 people, destroyed 25,000 buildings, and forced Florida to strengthen building codes statewide. 

"The real challenge in a hurricane is the window not being hit once, but being hit over and over and over," said Peter Dyga, president of Associated Builders and Contractors in South Florida. "This is the real big test."

CBS News' Strassmann met Dyga at his hotel project where workers were installing impact-resistant windows, which are lab-tested to withstand the impact of a two-by-four hitting them at a force of 140 mph. 

"These storms are strong storms. Mother Nature's gonna win in the end. And we just gotta hope and pray for the best," Dyga said. 

Miami Beach has three sandbagging stations, which have given away almost 30,000 bags of sand in the last couple days -- so much sand that the city ran out of bags. People have had to show up with their own bags. 

Fishermen seek shelter for boats in Florida Keys

Potential danger from Irma extends throughout the Florida Keys, which stretch 120 miles into the sea. 

Fishermen in the Keys have begun searching the mangroves, hoping to shelter dozens of boats from the storm. It's a long-established tradition.

"This is the heart of our operation," said commercial fisherman Gary Sands. "If we lose this, we're out."

It was in 1960, ahead of Hurricane Donna, that Sands first secured a fishing boat in the mangroves, reports CBS News' Elaine Quijano. Back then, it was Sands' father's vessel. And now, his fellow fishermen are helping him protect his boat. 

"It's a lot of friends, I got a lot of friends here," Sands said. "I got charter boat friends, lobster friends. It's a community, we're all sticking together. It's a nice community, it's really nice where we live." 

Sands, among other fishermen, say they do not plan to evacuate. They will stay near their boats in Key Largo.

States of emergency declared in Georgia and the Carolinas

Meanwhile, further north in Georgia, Gov. Nathan Deal is taking no chances. Deal has already ordered mandatory evacuations in Savannah and other coastal areas, which go into effect on Saturday, reports CBS News correspondent Don Dahler. 

Residents began boarding up and sandbagging houses and businesses in anticipation of the storm's arrival late Monday or Tuesday. Even if it makes a glancing blow, Savannah -- a historic jewel of the South -- could suffer considerable damage. 

Last October, Hurricane Matthew did not make a direct hit in Georgia, yet it still caused tens of millions of dollars in damage. 

Savannah has been fortunate when it comes to major storms, with only three storms making direct hits in more than 100 years. 

The governor has activated 5,000 National Guardsmen both to protect life and property as well as to assist with rescues.