Here is a report from tonight's BBC News, and it includes the following statements:
A school in Essex has banned triangular flapjacks, saying they are too dangerous.
The school has reviewed the shape and texture of the flapjacks and decided from now on the triangular one is banned and the only safe shape is square or rectangle.
The casualty of the flapjack attack has made a full recovery.
You can find more information on the story here, in which you'll learn that "Essex County Council said it did not give schools guidance on the shapes of foodstuffs." (If you're unfamiliar with the lingo, it might help to know what England calls "flapjacks" are what Americans call "granola bars" or "baked dirt.") [BBC]