Click and drop a few members of the staff into an empty wing of the hospital, then trap them inside the wing (cover the floor with a line of plants). There has to be no way for them to escape. Once they are all trapped, click on any or all of them, and fire them. Watch what happens. Different things happen to Doctors, nurses, etc. This always works in the demo, if the staff are trapped in the south-east wing and the narrow passageway is blocked with plants.