Character above terrain -> throws terrain

[Seidel]

2 characters height 2 are above a terrain height 3. What happens to them if an enemy throws that terrain into another terrain?

Thank you

[Negoldar]

Characters that are on a terrain feature that is thrown or destroyed by a throw will be placed on the ground in the same horizontal position they were in before the terrain feature was thrown. 

Page 24 of the rulebook has more details on this.