(Photo credit: Reuters/IOC/OBS)

CORTINA D'AMPEZZO, Italy -- U.S. ski great Lindsey Vonn had surgery on a broken leg after her bold bid to win Olympic downhill gold with a ruptured knee ligament ended in a horrific crash after 13 seconds on Sunday.

Vonn was being treated in the Ca' Foncello Hospital in the northern Italy city of Treviso after being flown there by helicopter after the high-speed crash in Cortina d'Ampezzo.

'In the afternoon, she underwent orthopedic surgery to stabilize the fracture sustained in her left leg,' the hospital said in a statement. A source told Reuters that she was being monitored in the intensive care unit where she could have more privacy, and stressed there was no threat to her life.

A helicopter took the 41-year-old to the hospital after she was strapped into a medical stretcher and winched off the sunlit slope.

It was the second time in nine days that she was airlifted off a mountain. She crashed in a World Cup race in Switzerland on Jan. 30 and suffered the ACL tear in her left knee.

Vonn, whose battle to reach the start line despite her knee injury dominated the opening days of the Milan Cortina Olympics, saw her unlikely quest halted in screaming agony on the snow.

Wearing bib number 13 and with a brace on the injured left knee, Vonn looked pumped up at the start gate.

She tapped her ski poles before setting off in typically aggressive fashion down one of her favorite ski runs on a mountain that has rewarded her in the past.

The 2010 gold medalist in the Vancouver Olympics and the second most successful female World Cup skier of all time with 84 wins, Vonn appeared to clip the fourth gate with her shoulder, losing control and being launched into the air.

She then barrelled off the course at high speed before coming to rest in a crumpled heap.

Vonn could be heard screaming on television coverage as fans and teammates gasped in horror before a shocked hush fell on the packed finish area.

The helicopter took Vonn initially to Cortina's Codivilla Putti Hospital for a medical assessment.

'The medical team responded immediately and the intervention time was excellent,' the International Olympic Committee said.

International Olympic Committee President Kirsty Coventry said everyone was thinking of Vonn.

'You are an incredible inspiration and will always be an Olympic champion,' she said.

The crash left the other skiers shaken.

'My heart goes out to her,' said Breezy Johnson, her U.S. teammate who won the first American medal of the Games. She had skied before Vonn, and her time held up as the other skiers attempted to better it.

'When you love the course so much and it hurts you like that, it hurts even more.'

Vonn had been hoping to become the oldest Alpine skiing Olympic medallist after winning two World Cup downhills this year and finishing on the podium in the other three.

Double Olympic gold medalist Tina Maze, working the race on TV for Eurosport, said Vonn had risked too much in her run.

'Of course if you're not healthy then the consequences are even worse, but we know all Lindsey,' she said. 'It's her decision that she wanted to do this no matter what.

'It's really tough for everyone here to see this and especially for her family and her teammates and everyone working with her. I mean it's terrible.'

Vonn's sister, Karin Kildow, said she Lindsey put her 'whole heart' into racing at the Olympics, especially as it was being staged on a course she loves so much.

'That's definitely the last thing we wanted to see,' she told NBC. 'When that happens, you're just immediately hoping she's OK, and it was scary.'

'She dared greatly, and she put it all out there.'

--Reuters, special to Field Level Media