A mother and daughter are dead after the boat in which they were riding with four others capsized in the Waccamaw River in northeastern South Carolina.

One person was still missing Thursday.

Georgetown County Coroner Kenneth Johnson says 19-year-old Shaquatia Robinson of Sandy Island died as did her mother, 47-year-old Lou Ann Robinson.

Shaquatia Robinson's 1-year-old son was found in the water after the Wednesday night accident and is listed in critical condition at a Charleston hospital.

Authorities are using a helicopter to look for a 17-year-old boy missing in the accident which occurred as the boat was nearing Sandy Island after crossing the river.

The boat's operator and her 5-year-old daughter were able to get to shore.