President Joe Biden and Federal Emergency Management Agency Administrator Deanne Criswel spoke with Lee County Commissioner Cecil Pendergrass Thursday to discuss response to the hurricane and ways the administration can support the county in the aftermath of Hurricane Ian.

The administration said it would assist in meeting immediate needs for search and rescue efforts, power restoration, helping to address challenges faced by local hospitals and problems presented by damage to roads and bridges, according to a statement from the White House.

-ABC News' Justin Gomez

The Sanibel Causeway, which connects Sanibel Island to mainland Florida, and the Matlacha Pass Bridge, which connects Pine Island to the mainland in Cape Coral, are not passable and will require structural rebuilds due to the storm, Florida Gov. Ron DeSantis said Thursday.

Officials have received reports of damages to other bridges. A team of 100 engineers is on site to do bridge inspections.

"I anticipate there will likely be other bridges that have suffered damage, but once bridges are inspected and determined to be safe, they will be reopened as soon as possible," DeSantis said.

Tampa International Airport announced it will resume commercial operations on Friday at 10 a.m. after shutting down due to Hurricane Ian.

Although an inspection of the airfield and facilities determined the airport did not sustain any serious damage during the storm, reopening Friday will give the airport and its partners, including the Federal Aviation Administration, Transportation Security Administration and airlines, time to take necessary steps to resume business safely, the airport said in a statement.

This includes bringing back aircraft and staff that had been removed ahead of the storm.

The airport had suspended operations at 5 p.m. on Tuesday ahead of Ian's landfall.

-ABC News' Amanda Maile

U.S. Coast Guard air crews rescued seven people in four separate rescue missions Wednesday night, Petty Officer Ayla Hudson told ABC News.

The rescues occurred in the Fort Myers and Tampa areas, Hudson said. The Coast Guard's search and rescue missions are still ongoing.

-ABC News' Victoria Arancio

Tropical Storm Ian is marching toward the Gulf Coast of the U.S., a region quite vulnerable to hurricanes.

The underwater geology of the Gulf of Mexico is what makes the Gulf Coast particularly unguarded to the massive influx of seawater, said Michael Brennan, acting deputy director of the National Hurricane Center, according to an article on Inside Science.

The symmetry of the Gulf of Mexico, with its shallow, sloping continental shelf, allows the storm surge to be pushed even higher onto land, Brennan told the outlet.

Because the land around the Gulf Coasts is typically flat, that exacerbates the flooding even more and allows the storm surge to travel farther inland, Brennan said.

"Of all of the hazards of hurricanes --- winds, rain, storm surges –-- surges are what can cause the largest loss of life," Brennan told Inside Science.

The Tampa Bay-St. Petersburg area, one of the regions bracing for Ian, is especially vulnerable to storm surge flooding but has avoided a direct hit from a strong hurricane since 1921.

Editor's Note: This post has been updated to reflect proper attribution to Inside Science.

-ABC News' Max Golembo