Stefan Wilson says there has been no anger over Justin Wilson's death because his accident was such an anomaly.
Wilson died Monday of a head injury suffered when a piece of debris from another driver's car struck his helmet.
Wilson was the 12th driver to pass through the accident scene at Pocono Raceway, and the nosecone from Sage Karam's car bounced into his open cockpit. The piece shot high in the air after striking Wilson.
His younger brother said before Sunday's season finale that the accident was "so freak, there's no one to be angry with."
Stefan Wilson also said his family has been overwhelmed by the support they have received from the IndyCar community, which is actively trying to raise funds for Wilson's wife and two young daughters.