Friend‘s family member sick, how do Japanese people handle this?

Two days ago my Japanese friend (male late 20s) got a phone call. He hasn’t said what it’s about except that someone is sick. He has been avoiding everyone and not responding to texts. He came to school because he doesn’t want to miss anything, but ignored everyone and just sat in a corner. I have no idea what to do. Is it culturally appropriate to just let him be, until he comes back on his own terms? Nobody where I‘m from would act like that, but I know Japanese culture is conflict avoidant and it’s seen as bad to show weakness.

Edit: Thanks for the input guys. I only see him at school, so I‘ll just say hi as usual and if he answers that’s cool but if not I guess I‘ll just leave him for the time being.