Alpha01
Hey Alpha01,
I am very sorry for your loss. As @jinx_58 has said, its best to inform and ask your school straight away. But from what I know, if you have a genuine reason with proof (which I am sure you do), you can resit the test and for example, for English, they might give you 2 different topics to choose from. Otherwise, they will use your total IA score and based on other students who have the same IA scores, they give you an average of their external exam scores as yours. This is what I have been told which could be wrong but it seems you have similar info as well. Again, your best bet is to ask your school.
Hope that helped and very sorry again.