Authorities are investigating 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 gangway, installed in 2021, gave way as an estimated 700 people visited largely unspoiled Sapelo Island, about 60 miles south of Savannah and 7 miles offshore.

Officials were on location in Georgia Sunday investigating the collapse of a ferry dock gangway that left seven people dead and six others critically injured Saturday.