Oblivious Tour de France spectator holding a cardboard sign causes a gnarly crash that sends dozens of riders to the ground on the opening stage

• Two dramatic crashes sent dozens of riders to the ground at the Tour de France on Saturday.
• In one incident a roadside spectator holding a cardboard sign caused riders to crash en masse.
• Several riders were injured, some abandoned, and many lost time on the opening stage.

Two horrific crashes on the opening stage of the Tour de France brought down dozens of riders on Saturday.

The first half of the stage, which started in Brest, in the northwest part of France, was relatively quiet with a small breakaway up the road. But as the race heated up chaos ensued.

The first big crash happened with about 45 kilometers to go when a rider at the front of the main bunch - Tony Martin on the Jumbo-Visma team - hit a fan's cardboard sign sticking out into the road.

The fan holding the sign appeared to be looking at the TV cameras - not at the coming riders. Martin went down hard, sending a chain reaction through the peloton.

Here you can see an overhead view of the first big crash:

-daniel (@cyclingreporter) June 26, 2021

Here you can see the crash from the front, with Martin on the far left:

-MUHQ News (@MUHQNews) June 26, 2021

Here's another look:

-NBC Sports (@NBCSports) June 26, 2021

It wasn't immediately clear how badly the riders were injured. Medical staff tended to the cyclists. Many had cuts and bruises but continued riding, albeit with bloody arms and legs.

The crash immediately forced at least one rider, Jasha Sütterlin of Team DSM, to abandon the race. Others were expected to have to stop as well. As for Martin he looked beat up but continued:

But then not long after, with about 7.6 kilometers to go, there was another big crash, this one at higher speed:

-Sporza (@sporza_koers) June 26, 2021

It wasn't immediately clear what happened in the second crash.

Many on social media criticized the fan with the sign, including pro riders:

-Jasper Stuyven (@Jasperstuyven) June 26, 2021

Many of the riders who crashed lost significant time.

The world champion, Julian Alaphilippe of the Deceuninck-Quick-Step team, went on to win the stage in Landerneau and take the leader's yellow jersey.