Officials say 58-year-old Frank Heinrichs of Swarthmore, Pa., was checking some of the 48 skylights at the school when he fell through the plexiglass skylight and 30 feet to the floor.
New Castle County paramedics spokesman Assistant Chief Richard Krett says Heinrichs was pronounced dead at the scene.
A Christiana School District spokeswoman say no children were in the gym at the time.
