It started off like an ordinary day for Diana, Princess of Wales.
She was in Paris, at the Ritz Hotel with her boyfriend Dodi Al-Fayed, an Egyptian film producer.
The pair had stopped at the hotel en route to London, after nine days of sailing around the French and Italian Riviera on his family’s yacht.
The paparazzi were everywhere.
To escape the flashing cameras, the Ritz Hotel’s deputy head of security Henri Paul had been instructed to sneak Princess Di and Mr Al-Fayed out around midnight.
A short while later, about 12.20am on this day in 1997, the princess and Mr Al-Fayed exited from the hotel’s back entrance in a hired black 1994 Mercedes-Benz driven by Mr Paul, with bodyguard Trevor Rees-Jones in the front passenger seat.
The group were headed to an apartment in Rue Arsène Houssaye, owned by Mr Al-Fayed’s billionaire father.
Tragically, they never made it.
After leaving the Rue Cambon, they drove along a road near the River Seine, with photographers on motorbikes in hot pursuit.
Then, they entered the Place de l’Alma underpass – where Mr Paul suddenly lost control of the car.
The car struck the right-hand wall before swerving to the left of the two-lane carriageway and colliding head-on with a pillar supporting the roof.
The vehicle was travelling about 105km/h – more than twice the tunnel’s 50km/h speed limit.
No one was wearing a seat belt.
Critically injured, Princess Diana reportedly murmured “Oh my God” over and over, and after the photographers and other helpers were pushed away by police, “Leave me alone”.
She was rushed to hospital where surgeons tried for two hours to save her life, but she died about 3am.
Mr Al-Fayed and Mr Paul were also killed in the crash.
Only the bodyguard survived.
In a statement, Buckingham Palace said the Queen and the Prince of Wales were “deeply shocked and distressed”.
Prince Charles broke the news of their mother’s death to Prince William and Prince Harry at Balmoral Castle in Scotland, where the royal family had been spending the summer.
A coronial inquest revealed Mr Paul had well over the legal level of alcohol in his blood.
It is also believed the aggressive actions of the paparazzi contributed to the cause of the collision.