Portuguese authorities say a 6-year-old girl has died after a yacht sank in the mid-Atlantic at night and she spent about seven hours in the water amid 10-meter (33-feet) waves.

The Portuguese Navy said in a statement Thursday that a French yacht carrying what was believed to be a couple and their two children sank after midnight.

The woman and a 9-year-old boy climbed into the yacht's lifeboat and were picked up by a merchant ship.

The Navy said a plane threw the man and girl an inflatable lifeboat and they were rescued after dawn, but the girl later died.