Belgian cyclist Michael Goolaerts has died after suffering a heart attack during Sunday's Paris-Roubaix race, his team has announced.
"I'm exhausted following this race", Sagan, the first rider as Frenchman Bernard Hinault to triumph here as a world champion, said.
Shortly after the 257-km race ended, Paris-Roubaix director Christian Prudhomme told Reuters that Goolaerts had to undergo a scan at the Lille hospital.
The 23-year-old, who rides for Verandas Willems-Crelan, suffered a cardiac arrest after being involved in a pile-up on the second of the race's 29 famed cobbled sections.
Quick-Step Floors: "Our thoughts go to the family, friends and team of Michael Goolaerts in these unimaginable moments of sadness". We kindly ask to refrain from speculation as we wait for an update on his situation. "He passed on Sunday day at 22.40 at Lille healthcare facility", his former group Veranda's Willems-Crelan mentioned in a declaration.
With 55km left, Belgium's defending champion Greg van Avermaet and Sagan attacked one after the other and the Slovakian quickly caught the three breakaway riders. Inevitably, it was the former who took the sprint, adding this Paris-Roubaix victory to that of his 2016 Tour of Flanders win. The race was also marred by several crashes that ended the hopes of outsiders Sebastian Langeveld and Matteo Trentin close to the Trouee d'Arenberg sector.
Goolaerts had been evacuated by helicopter after crashing about 150 kilometers (93 miles) from the finish.
Goolaerts crashed 109km into the 257km race and was found unconscious by race doctors. I said before the race that my goal was to do my best. In 2017, almost half of the riders did not make it to the finish in the Roubaix Velodrome.