On 4 May 2016, an Airbus A330-200 in the cruise in day VMC at FL390 in the vicinity of a highly active thunderstorm cell described by the crew afterwards as ‘cumulus cloud encountered a brief episode of severe clear air turbulence which injured 24 passengers and crew, seven of them seriously as well as causing some damage to cabin fittings and equipment. The Investigation was unable to determine how close to the cloud the aircraft had been but noted the absence of proactive risk management and that most of the injured occupants had not been secured in their seats.