Updated

A woman and two of her sons are improving at hospitals after they were seriously injured when a flight information billboard fell on them at an airport in Alabama.

A third son was killed Friday when the electronic board, weighing at least 300 pounds, fell at the Birmingham-Shuttlesworth International Airport.

The boys' mother, Heather Bresette, had broken ankles and a crushed pelvis. A hospital spokeswoman says she had surgeries over the weekend and was getting better. However, she was still unconscious Sunday and does not know that her son died.

The Bresettes, a family of seven, took a weeklong vacation in Destin, Fla., and were about to fly home to Overland Park, Kan., when the sign fell.