When is the next stage of the Tour de France?
Welshman Thomas, a former Olympic track cycling champion, suffered the indignity of being booed off the podium when he won the second of back-to-back stages in the high Alps to take his lead over four-time champion and teammate Froome to 1min 39secs.
Despite being helped back on his bike, and valiantly finishing only 13secs behind stage victor Geraint Thomas of Team Sky, the crash ended Nibali's bid to stay in contention on the race, which he leaves after climbing to fourth overall at 2:37 behind the British race leader.
He said: "Honestly I'm speechless. I wouldn't know what it was".
"I followed [Tom] Dumoulin and [Romain] Bardet".
The vulnerability of the Tour de France riders was highlighted when a smoke grenade was tossed into the middle of the peloton on the run-in to Valence.
Sunday's 15th stage is a 181.5-km road race from Millau to Carcassonne ahead of the second rest day and three stages in the Pyrenees that could shake up the overall standings.
Briton Geraint Thomas keeps the yellow jersey after finishing ahead of his main rivals.
Prudhomme said: "I heard the whistles on Alpe d'Huez, just as I did in the Vendée".
Fans have booed and whistled at Froome throughout the race and with the huge numbers of spectators lining the 21 hairpin bends up Alpe d'Huez, Sky discussed security for Froome on the climb with race organizers.
It was the calm after the storm following the Alpe D'Huez stage which saw Chris Froome accosted by a fan and Vincenzo Nibali forced to quit with a broken vertebra after a spectator outside of the barriers brought the Italian down.
The 31-year-old was too good for his opponents as he outlasted them to become a serious contender for the overall crown.
The 12st stage of the Tour de France is always one of the most special and Geraint Thomas's historic victory made Thursday's ride one to remember, however there were also a couple of unsavoury incidents.