Georgia authorities say they are investigating the "catastrophic failure" of a dock gangway that collapsed and killed at least seven people on Sapelo Island.

Multiple people were taken to hospitals, and crews from the U.S. Coast Guard, the McIntosh County Fire Department, the Georgia Department of Natural Resources and others were searching the water, according to spokesperson Tyler Jones of the Georgia Department of Natural Resources, which operates the dock.

Jones said a gangway at the dock collapsed and sent people plunging into the water. It happened as crowds gathered on the island for a celebration of its tiny Gullah-Geechee community of Black slave descendants.

At least 20 plunged into the Atlantic waters, where a strong tidal current threatened to pull them out to sea.

"There have been seven fatalities confirmed," Jones said on Saturday. "There have been multiple people transported to area hospitals, and we are continuing to search the water for individuals."

On Sunday, officials identified the victims as:

75-year-old Jacqueline Crews Carter of Jacksonville

74-year-old Cynthia Gibbs of Jacksonville

77-year-old Charles L. Houston of Darien

73-year-old William Johnson Jr. of Atlanta

93-year-old Carlotta McIntosh of Jacksonville

79-year-old Isaiah Thomas of Jacksonville

76-year-old Queen Welch, of Atlanta

What caused the Sapelo Island dock to collapse?

"It is a structural failure. There should be very, very little maintenance to an aluminum gangway like that, but we'll see what the investigation unfolds," Georgia Department of Natural Resources Commissioner Walter Rabon said at a news conference Sunday.

The gangway was installed in 2021, authorities said.

Seven people were killed in the collapse Saturday, and Rabon said three remained hospitalized in critical condition Sunday.

Rabon said "upwards of 40 people" were on the gangway when it collapsed, and at least 20 fell into the water. Rabon said none of the people killed were residents of the island.

Among the dead was a chaplain for the Georgia Department of Natural Resources, Jones said.

Resident Reginald Hall was one of the men who charged into the water and joined a human chain to rescue survivors. Speaking to FOX 5's Alex Whittler, Hall said that the dock's collapse was preventable and speaks to larger issues surrounding safety on the island.

"There’s an issue that has something to do with the compliance of those new docks that have only been in existence for three years," he said.

The ferry dock was rebuilt three years ago after Georgia officials settled a 2015 lawsuit by island residents, who complained that state-operated ferry boats and docks failed to meet federal accessibility standards for the disabled.

Ferry worker Ed Grovner said he complained to a ferry captain months ago that the gangway didn’t seem sturdy enough, but nothing happened.

"I couldn’t sleep last night," Grovner said. "My wife said I was sleeping, I was hollering in my sleep, saying, ‘I’m going to save you. I’m going to save you. I’m going to get you.’"

Rabon said he wasn’t aware of any prior complaints.

What is Cultural Day, and why do people gather on Sapelo Island?

Cultural Day is an annual fall event spotlighting the island's tiny community of Hogg Hummock, which is home to a few dozen Black residents. The community of dirt roads and modest homes was founded by former slaves from the cotton plantation of Thomas Spalding.

Small communities descended from enslaved island populations in the South - known as Gullah, or Geechee in Georgia - are scattered along the coast from North Carolina to Florida. Scholars say their separation from the mainland caused residents to retain much of their African heritage, from their unique dialect to skills and crafts such as cast-net fishing and weaving baskets.

In 1996, Hogg Hummock, also known as Hog Hammock, was put on the National Register of Historic Places, the official list of the United States' treasured historic sites. But the community's population has been shrinking for decades, and some families have sold their land to outsiders who built vacation homes.

Tax increases and zoning changes by the local government in McIntosh County have been met by protests and lawsuits by Hogg Hummock residents and landowners. They have been battling for the past year to undo zoning changes approved by county commissioners in September 2023 that doubled the size of homes allowed in Hogg Hummock.

Residents say they fear larger homes will lead to tax increases that could force them to sell land their families have held for generations.

Georgia Gov. Brian Kemp released a statement asking for all Georgians to pray for those who lost their lives in the collapse.

"Marty, the girls, and I are heartbroken by today’s tragedy on Sapelo Island," Kemp said. "As state and local first responders continue to work this active scene, we ask that all Georgians join us in praying for those lost, for those still in harm’s way, and for their families."

Both President Joe Biden and Vice President Kamala Harris released statements offering their prayers for the victims and their families.

"Jill and I mourn those who lost their lives, and we pray for the injured and anyone still missing," Biden's statement reads in part. "We are also grateful to the first responders at the scene. My team is in touch with state and local officials, and we stand ready to provide any and all assistance that would be helpful to the community."