My understanding is that it starts as an upper respiratory virus (mainly concentrated in the throat), leading to flu/cold-like symptoms and only those unlucky o

My understanding is that it starts as an upper respiratory virus (mainly concentrated in the throat), leading to flu/cold-like symptoms and only those unlucky ones that get it deep in their lungs attached to ACE2 receptors end up with a life-threatening lower respiratory illness requiring ICU and ventilator/ECMO due to immunity going berserk and killing off lung tissue with virus embedded in it, a cytokine storm.