The Black Saturday bushfire that destroyed Marysville could have been prevented if a power company had followed basic safety standards, according to an explosive coronial finding.

For the first time, power company AusNet Services has been held directly responsible in court for causing the 2009 bushfire, which killed 40 people, levelled hundreds of homes, and caused millions of dollars worth of damage.

CFA Fireman Rodney Ridd as the Murrindindi fire approaches his property in February 2009. Credit:Justin McManus

State Coroner Judge Ian Gray, in delivering an in-chambers finding nearly seven years after the disaster, outlined extraordinary details which have never before been aired in public.