it'll have an owner
so you go after the owner
You almost certainly will have to bring a case in negligence which erm means shwoing the owner has been negligent in allowing it to fall on your house
if it is owned by Chinese Govt any action will be barred on the grounds of sovereign immunity
try your house insurance and let them sue ( principle of subrogation)
so OK this same as - who do you sue if the local mag-lev railway has magneetised your dustbin and thrown it thro your front window ?
erm you cant in short
You have fallen into the trap of:
if you are lame - then there must be a claim ! ring 01077....
there may not be money at the bottom of every damage
( this is Law and not chatterbank so I dont have to pepper the script wiv frequent "wot dat den?" and "Fooooo!" in order to make it AB courant and readable)