Boonen has won the event three times in the past, but is currently going through a rough patch. Last week he also fell in the Ghent - Wevelgem race.
The riders were clearly nervous in the opening stage and this cannot have helped. The Belgian fell on his hip and was clearly in great pain. He was taken to Roeselare Hospital for tests. Boonen was said to be riding by the side of the road when a wave of riders escaped from the peloton. Boonen fell resulting in severe bruising.
Next Sunday is Paris - Roubaix, another cycling classic dubbed the 'Hell of the North'. It remains to be seen whether the Belgian will appear at the start, but chances are very slim.
Boonen's decision to quit from this year's Tour is a blow to his Omega Pharma-Quick Step team. Manager Patrick Lefevere: "The team has been decapitated. You should have heard me swearing. It's a hard time mentally for Boonen. He's been racing to catch up since December. I think he's finished for this spring."