How to get family to revoke decision.?

My eldest brother was kicked out today by our father because as my dad said to my mom "I did it for your safety." My brother has NEVER so much as threatened to hurt any of us and I don't think he ever would. Right now my brother is sitting in his car outside. He is probably cold, uncomfortable as all of his stuff is crammed in his car and he hasn't eaten today nor drank anything, not even after walking 11 miles. My family wanted my brother to get mental help but my brother refused and so they kicked him out until he does. Now I can only imagine my brother thinks we all hate him or are unsupportive or caring. I don't want my brother sitting in his car uncomfortable and malnourished and I think my family made a huge mistake kicking him out. That doesn't help solve anything. But, how to get my family to understand this?