Triggering a unit to "fall down" - possible?

Does anyone know if it is possible to create a trigger that would make a unit "fall down" backwards smoothly, without having to create 20+ units with different "Roll Angles". Thank you.

Animation - Play unit's Death animation.

Only realistic way without animating a fall animation, and importing the new model.

As far as I know there's no way to dynamically change the roll angle, unless if you could create a terrain deformation that would turn the unit around.