All sounds CC-by-sa Julien Jorge, produced with the following samples.

whistling-1:
whistling-2:
CC-by dobroide http://www.freesound.org/people/dobroide/sounds/13779/

explosion-1:
explosion-2:
explosion-3:
explosion-4:
CC-by: WIM http://www.freesound.org/people/WIM/sounds/23015/
