Chris Froome's Tour de France title defence is over after the Team Sky leader abandoned the race on the cobbled fifth stage following three crashes in two days.
The 29-year-old Briton had tumbled to the tarmac on Tuesday's fourth stage, damaging his wrist.
He started the fifth stage from Ypres to Arenberg Porte du Hainaut, which took place in torrential rain that slickened the roads.
Froome crashed early on the route before a second crash with around 70-kilometres remaining saw him end his defence.
He consulted Team Sky doctor Alan Farrell before taking his place in the back of the Team Sky car.
The stage commemorates 100 years since the start of World War One and features many of the cobbles used in the Paris-Roubaix one-day race 'the Hell of the North'.
Wet weather forced race organisers to remove two of the nine cobbled sections, but Froome's falls came prior even to the first section of cobbles he had been dreading since the route was announced last autumn.
The sad sight of Froome, dominant in winning the 2013 Tour, grimacing by the roadside was reminiscent of Bradley Wiggins' withdrawal with a broken collarbone in the first week of the 2011 Tour.
Froome fell on his left side during June's Criterium du Dauphine and again on Tuesday, and then on his right.
The Team Sky rider was dragged back to the main pack after 42km as seven riders, including world time-trial champion Tony Martin (Omega Pharma-QuickStep), were up ahead.
The frenetic pace and difficult conditions set-up a compelling day's racing, with Froome a victim of misfortune as a further tumble proved too much and he exited the Tour.
His team-mate Bernhard Eisel had also crashed and was waiting for Froome, but the Briton clambered gingerly into the rear of the Team Sky sports car.
Devastated to have to withdraw from this years TDF. Injured wrist and tough conditions made controlling my bike near to impossible.— Chris Froome (@chrisfroome) July 9, 2014
Team Sky principal Dave Brailsford said prior to the start that Richie Porte would be a protected rider, like Froome, as an insurance policy.
It is likely the Australian will now be Team Sky's leader, although Geraint Thomas could also be given a chance to prove his potential.
Froome's fate again highlighted Brailsford's call to omit Wiggins, the 2012 winner, from Team Sky's squad.
Wiggins was ninth in Paris-Roubaix in April and won May's Tour of California but was not selected.
The first cobbled section was due after 87km of racing, with organisers removing sector seven and five - two sections totalling 2.4km - reducing the stage distance to 152.5km, 3km less than originally planned.
Froome joins Mark Cavendish in exiting the Tour after the Manxman's crash on stage one to Harrogate.
Cavendish had shoulder surgery on Wednesday which rules him out of the Commonwealth Games.
Thomas and Simon Yates (Orica-GreenEdge) were the remaining Britons.
Froome was not the only rider to be unseated on a difficult day, with Marcel Kittel (Giant-Shimano), the winner of three of the opening four stages, also tumbling.
Froome's supremacy in the mountains earned him the 100th Tour title in 2013, but a duel with two-time winner Alberto Contador will now have to wait until 2015, at least.
Contador's Tinkoff-Saxo team wrote on Twitter: "@chrisfroome we wish you a swift recovery #TDF. We were looking forward to the battle in the mountains @letour"
Schleck has surgery on damaged knee
Andy Schleck, the 2010 Tour de France champion who abandoned the 2014 race on Tuesday, has had knee surgery.
Schleck had a MRI scan to determine the full extent of the injury before going under the knife in Basle, Switzerland, but it is still too early to tell when he will return to racing.
Trek Factory Racing said: "Andy Schleck's knee is severely damaged: there are partial ruptures in the collateral and cruciate ligaments, the meniscus is torn and an injury to the articular cartilage has been diagnosed during the procedure, raising further concern about Schleck's rehab."
Schleck was a shadow this year of the rider who duelled with Contador before inheriting the 2010 title when the Spaniard's result was ruled void by an anti-doping violation.
He said: "I'm feeling pretty bad, to understate it. I'm gutted.
"My knee looks like there's been an explosion inside. I'll be on crutches for at least two weeks and from there on we will see.
"I cannot ask for a detailed time line right now, and that is hard to deal with.
"There's nothing else I can do. Acceptance is the first step of my rehab and I'm working on that now. There's lots of work to be done before I'll be back, but I'm used to fighting back."