My brother is diagnosed terminal brain tumor, what are the steps I should take?

Hi, not an electrician myself, but my brother (31M) is an electrician (paid hourly) for the Seaspan company for the last 2 years, and is under IBEW union. To keep things short, he was diagnosed with terminal brain tumor just this week and our family members are attempting to sort things out as he is currently cognitively incapacitated.

What are the steps I need to take to alert the company or the union in order to properly apply for a leave of absence and what kind of assistance/benefit programs do I need to be aware of if any?

Thanks in advance