Brother wrecked my car but won’t tell me what happened

My brother wrecked my car and won’t tell me what happened. He suffers from severe mental illness. The car is totaled. The car is in my name and the car insurance is under my name. He was not on the policy. Can I still file a claim with my insurance company if I don’t know what happened and how the accident happened? I’ve tried to ask him many times about what happened but he won’t give any information. This happened at least 8 month ago.