London - The man leading the inquiry into a train crash in which seven people died has "withdrawn" because he has a job which "could be thought to compromise his appointment", the Health and Safety Commission said yesterday. The commission had appointed Dr Tony Barrell to head the inquiry into the Southall rail crash in west London on a section of rail route where Heathrow Express trains will run alongside mainline trains when the airport branch opens next year. Dr Barrell is a non-executive director of BAA, which operates Heathrow and is behind the building of the new airport rail link.