How did lady Diana die?

Lady Diana died because her friend Dorothy and Diana walked on a highway, a guy who was in alcohol drove the car and couldn't slow down and crashed them. But Dorothy survived and Diana didn't. People over the world have discussed that Charles (husband) did the murder. But then the police caught the real murderer. Though in the very first past before Charles was going to marry Diana, Charles loved Camilla. (Lover). Some people had doubts about it. After Charles married his second wife as usual it was Camilla.