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.

Dock collapse on Sapelo Island About 700 visitors were in attendance at Sapelo Island, about 60 miles south of Savannah, before the collapse which tragically killed seven people and left three in critical condition.

The aluminum gangway suffered structural failure as historic Sapelo Island hosted an event celebrating its Gullah Geechee history and culture.