The stack effect can also exacerbate the spreading of fire, especially in tall buildings where design flaws allow the formation of unwanted drafts. Examples include Kaprun tunnel fire, King's Cross underground station fire and the Grenfell Tower fire, as a result of which 72 people died. The latter of these was in part exacerbated by the stack effect, when a cavity between the outer aluminium cladding and the inner insulation inadvertently formed a chimney and drew the fire upwards.