At least seven people were killed on Saturday in an emergency at a ferry dock on Sapelo Island, Ga., the authorities said. Mark Deverger, the McIntosh County volunteer fire chief, confirmed the deaths but said he did not know the specifics of what happened.

The Georgia Department of Natural Resources responded with local, state and federal agencies to the Marsh Landing Dock on the island, where at least 20 people went into the water when the collapse occurred. As of about 8 p.m., authorities said they believed seven people had died.