SARASOTA, Fla. -- Sarasota County issued a mandatory evacuation for all barrier islands, mobile home parks and low-lying areas Friday afternoon. The county opened three shelters and is expected to open four more.

County officials are worried about storm surge up to 15 feet in the worst-case scenario.

We checked Siesta Key and found many visitors and locals are getting out.

A weeklong vacation on Siesta Beach has been cut short for Bryan Scurto and his friends.

“Now it’s mandatory, so we're going to go,” Scurto said.

The group started packing to head back to Chicago when voluntary evacuations of the barrier islands were issued Thursday.

Scurto says Irma made them nervous.

“It’s something you shouldn’t take lightly. It’s Mother Nature don’t know what she’ll do and switches paths again, better to back be gone,” he says.

The Mendoza family visiting from Argentina evacuated from their Naples hotel and were told to go to Sarasota.

“They told us yesterday here was OK, that it would be a grade 2, We're waiting for instructions to see what happens,” says Natalia Mendoza.

The Mendozas had plans for the beach, but the county closed the beaches at 2 p.m. But it’s not like many people are interested in heading to the beach.

We drove through Siesta Key before the closing and found plenty of open parking spaces, and the streets are virtually empty.

“I think a lot left and those that are here are die-hards and not leaving,” says Allison Tan.

Tan drove from Lakeland to board up her Siesta Key home. "We’re afraid the bridges go out and we won't be able to get on the island.”

She threw in a quick stop for her son; it’s his 13th birthday.

"He wanted to spend the afternoon on the beach, so we gave him half an hour.”

Some last moments in the sunshine before Irma comes barreling through Florida.

Sarasota emergency officials have given the barrier islands until 8 p.m. Saturday to evacuate. They warn that once sustained winds reach 45 mph emergency crews will be off the road.

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