The incident took place on the fourth lap of the race. Simonsen, a seven-year veteran of Le Mans racing, spun about 10-minutes into the race, hitting safety barriers at the Tertre Rouge bend.
The No. 95 Aston Martin that Simonsen co-drove along with teammates Christoffer Nygaard and Kristian Poulsen has officially retired from the race. Our condolences to all those close to Simonsen.
A video showing the first 10 minutes of the race can be found below, though be advised that it ends with the Simonsen's accident, along with an official statement from race's governing authority, Automobile Club de l'Ouest.
2013 24 Heures du Mans Official Statement
At 15h09 the No.95 Aston Martin Vantage GTE, driven by Allan Simonsen of Denmark, exited the track at high speed at the Tertre Rouge corner on his fourth lap of the race.
The driver was immediately attended on the scene by the doctors from the Automobile Club de l'Ouest's Medical Service.
In a serious condition, Allan Simonsen was transferred immediately to the Circuit Medical Centre where he died soon after due to his injuries.
Allan Simonsen's family has been informed immediately by David Richards, Principal of the Aston Martin Racing team.
Allan Simonsen, an experienced driver aged 34, had taken part in seven 24 Heures du Mans.
His team mates in the No.95 car were his fellow countrymen, Christoffer Nygaard and Kristian Poulsen.
The Automobile Club de l'Ouest wishes to express its great sadness following this incident, and extends its deepest condolences to the family and those close to Allan Simonsen.
The Automobile Club de l'Ouest will make no further statement while the exact reasons for the accident are still being wholly determined.