The cause of death for Prince William and Prince Harry's cousin Rosie Roche has been reportedly revealed. Roche was killed by a "traumatic head injury," according to the Daily Mail, The Independent and other outlets, which cite the Wiltshire and Swindon coroner. She was 20 years old. The Sun reported that Roche died on July 14. She was reportedly found by her mother and sister after she had been packing for a trip with her friends. Wiltshire and Swindon coroner's court has opened an investigation into her death. The Sun reports that the inquiry was "adjourned until October 25.