* Danish driver killed after Aston Martin crashes
* Audi lead but number one car hits problems
* Toyota second and third after 10 hours
Audi's Tom Kristensen led a tragedy-tinged Le Mans 24 Hours race into the darkness of Sunday morning after fellow-Dane Allan Simonsen was killed in a crash only minutes into the endurance event.
The first race fatality in 27 years at Le Mans cast a pall over 90th anniversary celebrations for the race on its 81st running at the La Sarthe circuit near the western French cathedral city.
Simonsen's Aston Martin team vowed to carry on and win their GTE Am class in tribute to the 34-year-old, who crashed heavily into the barriers at Tertre Rouge on his third lap, at the request of his grieving family.
Jean Todt, president of the International Automobile Federation (FIA), and organisers expressed their "profound sadness" after the experienced Dane was pronounced dead at the circuit medical centre.
The most recent fatality connected with the race was Frenchman Sebastien Enjolras, killed during pre-qualifying in 1997, but the last driver to die during the race was Austrian Jo Gartner in 1986.
Le Mans, the scene of motor racing's deadliest accident when at least 80 people died and scores more were injured in a 1955 disaster, ranks with Indianapolis and Monaco as one of the sport's great glamour events.
After the accident, the next 58 minutes were led by the safety car as repairs were carried out to the barriers at Tertre Rouge until green flags signalled a return to racing on a glistening track dampened by showers.
There were to be more safety car interludes over the coming hours while Audi, the dominant team of the last decade, suffered setbacks as they took the battle with Toyota into the night.
Germany's Andre Lotterer led at the time of the accident in the number one Audi R18 e-tron quattro diesel hybrid but his hopes of a third successive victory with team mates Marcel Fassler and Benoit Treluyer suffered a knockout blow at the quarter distance.
A problem with the motor generator kept the car in the pits for 43 minutes while mechanics worked to fix it and it eventually returned to the track in 24th place and 12 laps behind.
After 10 hours, it had moved up to 15th but still 11 laps down on the leader.
The number three Audi also hit problems, dropping to fourth place after limping back to the pits with a right rear puncture and then also requiring repairs in the garage.
While the number one car was stalled, the number two Audi took the lead with Denmark's eight times winner Tom Kristensen at the wheel in the car he shares with Britain's Allan McNish and Frenchman Loic Duval.
At the 10-hour mark, Kristen's Audi was a lap clear of the second placed Toyota of Frenchman Stephane Sarrazin, Britain's Anthony Davidson and Swiss driver Sebastien Buemi.
The Toyota of Austrian Alexander Wurz/Frenchman Nicolas Lapierre and Japan's Kazuki Nakajima was third.
Audi, winners at Le Mans for the past three years and 11 times in the last 13, had started in 1-2-3 formation after dominating Wednesday and Thursday qualifying with rivals Toyota in fourth and fifth.