A 10-month effort to find out how a Briton was killed while building Qatar’s Khalifa stadium for the World Cup has been met with a wall of silence from the Qatari authorities and multinational building contractors, leaving his relatives distraught and angry. Zac Cox died in January after he fell 40 metres when his safety equipment failed. His family have been told that a report containing vital information about the circumstances of his death exists, but it has not been passed on to them or the British coroner investigating his death...The body overseeing the World Cup, the Supreme Committee for Delivery and Legacy, has never communicated with the family about the accident. The German construction multinational Pfeifer – which was contracted to build the stadium roof walkways on which Cox was working – has also failed to pass on information and respond to family emails setting out their concerns. The British police have been unable to extract information from an opaque Qatari justice system, or the array of firms involved in the work...Human Rights Watch has claimed that more than 300 people have died, largely due to heat and exhaustion, on the project, although the numbers are disputed...