Geraint Thomas, who was aiming for the overall win in the Giro d'Italia, injured his left leg early in stage 3 and lost over 12 minutes on Mount Etna.

Video taken by fans along the roadside showed the group sprinting down the city's wide boulevards. It showed Thomas crashing on the right side of the road after hitting Bidon with his rear wheel and losing control.

Thomas was able to get back up and the race was briefly suspended. However, he fell off before the final climb to Etna, losing 12 minutes and 19 seconds.

After not participating in the Tour de France, Thomas' hopes of reviving his Grand Tour campaign in Italy in 2020 were dashed by these unforeseen accidents.

Thomas' disappointment was compounded by his fourth-place finish in the opening time trial, which gave him a significant advantage over nearly all of his GC rivals.

On top of that, his teammate Filippo Ganna won the opening stage, and in front of Etna, he was hoping that he might be able to cede the pink jersey to Thomas, who started Monday's stage 23 seconds behind him.

But after a flying start, Ganna was forced to help close the gap to Thomas as much as possible, while teammates Salvatore Puccio and Rohan Dennis also tried to help limit the damage.

"After two very good days for us, Bidon hit the front wheel just 1.5 to 2 km into the neutralized section and crashed," Ineos sport director Matteo Tosatto said after the race.

"Gelant did not immediately feel pain in his left leg, and it was better when he got on the bike after the start.

"But the pain got worse on the steep climb in the last 45 km and he had a bad day.

"So he preferred to climb at his own cadence, finish the stage, and wait for the doctor's analysis."

Thomas is no stranger to crashes at the Giro d'Italia ruining his GC candidacy: in 2017, he crashed badly in a group crash caused when another rider got tangled up with a poorly positioned police outrider bike.

As for the wider impact on the Giro, Monday was a tough day for the Briton, who is looking for his second overall win in three years, as Simon Yates (Mitchelton-Scott) also lost time.

As the best time triallist in the 65-km Grand Tour, Thomas had been the reference point for the other favourites, but now the Giro was suddenly wide open again.