Entitlement to service connection for the cause of the Veteran's death is remanded.

Board reasoning

The Board remands for additional development before adjudicating the claim, including obtaining an autopsy report, updating toxic exposure risk activity information, and securing an etiological medical opinion addressing whether trauma to the spine with related conditions contributed to death and any relation to toxic exposure. It notes prior references to Stegall and Bowery-type considerations as part of ensuring the record is complete and that any opinions are adequately explained with rationale.