Even as you are jumping down, you realise that the fireball is probably due for another pass in a few moments. You turn to return the way you came, you see the fireball approaching at incredible speed.
The air is already growing hot.
With the howling, burning sound, much louder now you are in the echoing, tunnel, drilling into your brain, and blinding light reflecting from every angle, you fall to your knees. With hands futilely covering your ears, and eyes screwed shut, you are powerless to prevent the ancient arcane trap from incinerating your body.
All that remains is a black smear of ash, and even that is swept clean when the fireball makes it next pass.
Go back and try a different choice!