What happens when a bodily claim injury is made against someone who is now incarcerated?

Didn’t get much response in the legal subreddit so thought I’d try here.

So I’m my brothers POA. He’s schizophrenic, homeless and lives off of disability. He was living out of his car.

He ended up having a freak out while driving and caused 3 or 4 cars to crash. No one was injured enough for an ambulance to be called or anything. My brothers car was the only one that got totaled.

About a week later he was arrested for something more severe but unrelated. He’s currently at a psych ward for 90 days because he was deemed incompetent to stand trial.

Even though he’s homeless he uses my address for his mail. I received a letter in his name from his insurance stating a person who was injured at the accident has hired an attorney for bodily injury. They need my brothers permission to release his policy limits.

1. how are they going to get my brothers permission when he’s likely going to be in a psych facility or prison for the next few years?
2. As his POA, am I responsible for handling this? I’m scared to communicate with them because I don’t want them coming after me for money or responsibility.
3. My brother has nothing to his name. No assets, only a few thousand in disability money. So what happens now if people try to sue him for injury?