Helicopter causes crash at Giro d'Italia forcing Luca Wackermann out with suspected back fracture

Italian Luca Wackermann was forced to withdraw from the Giro d'Italia with multiple injuries following a big crash in Tuesday's fourth stage caused by a low-flying helicopter.

The crash, which brought down Wackermann and Dutchman Etienne van Empel of the Vini Zabu-KTM team, happened at the end of the stage when a barrier was blown over by the draft from the helicopter and struck the two riders.

A statement from the Italian team said Wackermann, 28, had suffered concussion due to a head injury, as well as a fracture of the nasal bones, multiple contusions to the face, on the chin and on the right knee.

He also sustained multiple bruises to his arms and legs and a suspected back fracture.

"Wackermann will spend the night in the hospital kept under observation and losing that chance to live a dream vanished because of an episode that could have brought some heavier consequences," added the statement.

he professional cyclists union urged the UCI, the sport's ruling body, to investigate the incident. "We have talked directly with Luca Wackermann and will be at his side to get justice after what happened yesterday at the Giro," a statement from the CPA said. "CPA has requested an investigation on what happened to the UCI. These kind of accidents are intolerable."

Frenchman Arnaud Demare edged out Peter Sagan in a bunch sprint to claim victory.

The last 30km of the 140km stage were flat, offering opportunities for the top sprinters and it was Demare who powered across the line fractionally ahead of Sagan.

Slovakia's Sagan had to settle for second place again as he did on stage two. Italian Davide Ballerini was third.

Portugal's Joao Almeida (Deceuninck-QuickStep) retained the pink jersey and opened a two-second lead over Ecuadorean Jonathan Caicedo courtesy of picking up a couple of bonus points in an intermediate sprint 25km from the finish line.

Earlier in the day, pre-race favourite Geraint Thomas abandoned the event after his crash in the neutral zone on Monday left him with a fractured pelvis.

Sagan's Bora-Hansgrohe piled on the pressure in the day's main climb, the Portella Mandrazzi, hoping to soften up the Slovakian's main sprint rivals.

It worked to some extent but there was still enough threat to Sagan in the final sprint, as Groupama-FDJ's Demare showed.

"I wasn't sure that I'd won when I crossed the line. It was so tight. It's fantastic to have won a Giro stage already in the first days of the race," said the Frenchman, who also won a Giro stage last year.

Sagan now has an incredible 30 second-place stage finishes in Grand Tours, along with 16 stage victories.

"Today, I went all out for the win. I didn't know who was first, second, or third, we all came to the line together and we had to wait for the photo-finish," he said.

"At times I won by a few centimetres, and at times it was like today."