First Minister Alex Salmond said he was "shocked and deeply saddened" by the accident, which occurred in the sports block of a school near the Scottish capital Edinburgh.
"Police in Edinburgh responded to Liberton High School after a wall within the building collapsed, injuring a female pupil at 10:00am," a spokesman for Police Scotland said.
"She was treated by ambulance staff on the scene, but was pronounced dead."
In 2011, a 15-year-old girl fell down a lift shaft at the same school, suffering three fractured vertebrae, bruising on her back and a sprained wrist.
Liberton High School was also hit by tragedy in December, when a pupil, 13-year-old Jamie Skinner, died after collapsing during a youth football match.