An AAIB investigation, conducted in private though publically reported, is to prevent future accidents, does not consider blame and only publishes edited output from interviews.
A coroner in England and Wales examines the circumstances of all deaths. While a hearing would not occur if someone died in their sleep for a clear medical condition it is naive to expect there not to be a hearing after multiple untimely fatalties.
Some posters should reflect if they would take a different line if their own 5 or 5 year old children had died a sudden an physically violent death.