MOBILE, Ala. -- Joe and Annie Horn remember the devastation that accompanied Hurricane Frederick as it galloped across Alabama 25 years ago this week, killing five and virtually wiping out the historic fishing village on Dauphin Island, south of Mobile. Their home on the island was wrecked, and the long bridge connecting the island to the mainland was destroyed.

And Scott Wolf remembers what happened when 1995's Hurricane Opal, originally headed west toward Mexico, made an abrupt right turn and made landfall near Pensacola, Fla. His home on Pensacola Beach was damaged, and he couldn't return to the island for a full year.

"There was three feet of sand here," he said. "They had to move it out of here with a bulldozer."

Santa Rosa Island, on which Pensacola Beach sits, and Dauphin Island are barrier islands, narrow strips of sand, dirt and grass tufts that run parallel to a mainland shoreline. These low-lying islands are especially vulnerable to hurricanes and tropical storms, less a barrier than a speed bump to the towering waves and storm-surge waters as they crash toward the mainland.

And both of these islands are, for the time being, squarely in Hurricane Ivan's sights. The powerful storm, as of last night, was slogging north through the Gulf of Mexico and expected to make landfall on the Gulf Coast sometime tomorrow.

Ivan has already been blamed for nearly 70 deaths in the Caribbean and is prompting evacuations from New Orleans to Florida's panhandle. Tourists, residents and seasonal employees were packing up, skipping town and jamming highways in the process.

Last night, the storm was projected to make landfall at the Mississippi-Alabama line, taking the storm right over Dauphin Island, which like Pensacola Beach was to be evacuated by this morning. Even if landfall is in Alabama, Pensacola Beach could suffer, because the portion of the hurricane that's east of the eye is more dangerous than the western half.

Other small coastal islands, like upscale Ono Island in Alabama and Florida's Perdido Key, a vacation spot, also have been evacuated.

Yesterday, the Horns spent the morning and afternoon securing their beach home, which faces east, toward Mobile Bay. As they packed for higher ground, they pondered what means most to them, and what gets left behind. Family photo album? Got it. Insurance papers and checkbook? Got it. Deed to the house? Yep. Lawn mower? Tossed in the back of their pickup.

Fishing boat and dozens of assorted fishing rods? Well, naturally.

"We may have to fish to eat," Annie explained. The rest of their belongings stayed in the home, which is built on thick stilts to minimize water damage.

"Anything else can be replaced," she said, just before she and her husband hopped in their truck and sped away. "Stuff is just stuff."

Others weren't so discriminating. Moving vans were a common sight yesterday, as some homeowners decided to take everything along.

As has been the routine in southern Florida for the last month, people in coastal communities from St. Marks, Fla. to Morgan City, La., boarded up homes and hoarded gasoline and water, creating lines at hardware stores, supermarkets, gas stations and pharmacies.

Pensacola, a town that subsists on tourists and the military, yesterday found itself without either. Beaches were bare and restaurants were mostly empty as employees prepared for Ivan by shuttering windows and removing outdoor decorations -- the giant plastic shark that graces the deck at Flounder's Chowder House, for instance.

Navy and Air Force bases evacuated more than 3,600 military personnel to Kentucky, Tennessee and Georgia. Fighter jets stationed there were flown out of state.

The flashing sign at the far side of the toll bridge connecting Gulf Breeze, Fla., and the beach told the rest of the story: "Welcome to Pensacola Beach," it said. "Prepare for Ivan now."

Wolf, who works on an offshore oil rig that also was evacuated, said he expects much of Pensacola Beach to be under sand, water or both come tomorrow evening. In some spots, the island is barely 1,000 feet across, narrow enough that you could jog from the north side to the south without breaking a sweat.

"With Opal, everything was damaged," he said -- hotels, beach homes, restaurants, gas stations. Opal's storm surge -- an abrupt rise in sea level caused by a tropical storm -- tore through the island, lifting not only tons of sand but also chunks of roadway with it. For months after the hurricane, asphalt lay on the white beaches in shiny black pads.

That's why, with the help of a federal grant, Mark and Valerie Sigler built their dome-shaped house on Pensacola Beach two years ago. The luxury rental home, profiled in national architectural journals and television shows, is supposed to be hurricane-proof because of its aerodynamic shape, and can withstand winds of up to 300 mph, far more than a hurricane could produce.

This week, a group of eight vacationing newlyweds was renting the home, hoping to have "one last week of fun" before married life sets in, said John Steiger, of Cincinnati.

Instead, he and his friends were drafted yesterday to haul sandbags and install plywood on the building's oddly shaped windows.

Hurricane-proof is not the same as waterproof, as it turns out. Their long-planned vacation, like many others, has now taken a turn out of Ivan's way.

"We're going to St. Augustine," Steiger said.