French authorities have launched an investigation after a fan caused dozens of cyclists to crash during the Tour de France on Saturday!

The disastrous fall was caused by a woman standing on the roadside of the Tour’s opening stage. She stepped in front of the racing pack holding a cardboard sign, appearing to display a message for the television cameras.

According to the race’s video coverage, the sign hit German rider Tony Martin who was cycling near the head of the pack. Martin fell, which led to the subsequent crash of dozens of riders behind him.

Check it out below!!