PORTSMOUTH, Va. -- The United States Coast Guard said a 4-year-old girl was rescued after becoming separated from her family while swimming with her grandfather near their sailboat in Herring Bay, Md., Tuesday evening.

Authorities said the girl's grandmother called the Coast Guard about 7:10 p.m. after she received a cell phone call from another child in the boat who reported Chuck Thompson, 60, and the young girl missing.

Members from Coast Guard Station Annapolis, Maryland State Police, Maryland Natural Resource Police and Anne Arundel Fire Rescue immediately began searching. Coast Guard search-and-rescue controllers coached one of the children on the boat to turn on the vessel's GPS and pass along their location.

A state trooper on shore was the first to see the swimmers in the water. The trooper reported that Thompson was faced down in the water and the child was moving around.

A Coast Guard boat picked up both swimmers and performed CPR on Thompson until a local emergency crew arrived. He was taken to Calvert Memorial Hospital, where he was pronounced dead.

The child was wearing a life vest, while Thompson was not. The girl was released to her parents.