The seven people killed Saturday in a gangway collapse on a Georgia barrier island were all in their 70s, except for one woman in her 90s, the coroner said Sunday.

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

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.