Authorities are working to identify the cause of a partial ferry dock collapse on Georgia’s Sapelo Island that turned a day of celebration into tragedy, leaving at least seven dead and six critically injured as crowds gathered for a cultural festival.

The collapse happened as crowds gathered on the island for a celebration of its tiny Gullah-Geechee community of Black slave descendants.

At least seven people were killed Saturday after part of a ferry dock collapsed on Georgia’s Sapelo Island, The Associated Press reported, citing a spokesperson for the Georgia Department of Natural Resources.

Seven people are believed dead after a gangway that's part of a marina collapsed on Sapelo Island, Georgia, on Saturday.

ATLANTA − At least seven people were killed after part of a boat dock collapsed, sending at least 20 into the Atlantic waters off the coast of Georgia on Saturday. U.S. Coast Guard ships were searching through the night for missing people.

At least seven people were killed on Saturday when the gangway of a ferry dock collapsed on an island in Georgia, forcing at least 20 people into the water, the authorities said. The deaths on Sapelo Island were confirmed by Mark Deverger,

At least seven people have died after part of a ferry dock collapsed in Georgia's Sapelo Island on Saturday, local authorities say. Georgia's department of natural resources, which operates the dock,