- St. Moritz hosts World Championships
- Swiss resort boasts steepest start gate
- Ski showpiece runs until February 19
- Vonn misses out in opening race
(CNN)Free-falling out of the start gate and accelerating to 90 miles per hour in just six seconds.
It's a chilling prospect and it's just the beginning of the men's downhill course in St. Moritz.
The start hut is cut into a rock face and the slick slope is so steep -- 100% or 45 degrees -- TV cameramen must abseil into positions wearing crampons.
But the one skier able to conquer their fear and harness this breakneck speed will be crowned world downhill champion for the next two years.
The race is the highlight of the 2017 World Championships, which start this week in the chic Swiss town.
St. Moritz, the jewel of the Engadin valley, has been a longtime destination for the jetset and draws a well-heeled international clientele to its fine-dining restaurants and five-star hotels.
Often dubbed the "home of winter sports," St. Moritz has hosted two Winter Olympics and four previous World Championships.
A total of 600 athletes from more than 70 countries will compete across six alpine skiing disciplines -- slalom, giant slalom, super-G, downhill, super combined (downhill and slalom) and the team event.
Outside of the Olympics, it's the biggest event in the sport and carries more cachet than the World Cup circuit.
"It's winning, basically, the Olympics minus all the other sports -- that's what the World Championships is for us. It's big," Mikaela Shiffrin, who leads the World Cup overall and slalom standings, told CNN's Alpine Edge.
The 21-year-old American is going for a third straight slalom world title after winning gold in Schladming in 2013 and Beaver Creek two years ago. She also won the Olympic slalom gold in 2014, and is aware she has set herself a very high benchmark.
"Not winning stinks -- it makes me feel like I've done something wrong," Shiffrin adds.
But the headline attraction will be her compatriot Lindsey Vonn, the second most successful ski racer of all time -- male or female -- with 77 World Cup wins, behind only Sweden's Ingemar Stenmark (86).
Speed queen Vonn, the 2010 Olympic downhill champion, won her only world title in 2009 and is back on the circuit following a broken arm and severe nerve damage to her right hand sustained in a crash shortly after returning from knee surgery.
Vonn won in only her second race since returning to the circuit in Garmisch-Partenkirchen in Germany in January, but crashed in a downhill at Cortina d'Ampezzo in Italy this month.
In St. Moritz Tuesday, she skied out during the opening run of the World Championships' first race -- the women's super-G -- after trying to regain grip on her pole.
"I just kind of lost my concentration there for a minute," Vonn, the 2015 bronze medalist, told reporters. "I stayed on my feet, so that was the important thing."
Austria's Nicole Schmidhofer won the gold medal from Tina Weirather of Liechtenstein and home favorite Lara Gut in perfect conditions, after two days of heavy snow had canceled the men's and women's downhill training sessions.
Defending champion and Olympic gold medalist Anna Veith didn't make the second run after missing a gate.
The women's downhill start is lower than the men's but still a considerable test of skill and stamina.
Vonn's main rivals on Sunday will be World Cup overall champion Gut and Slovenia's Ilka Stuhec, this season's World Cup downhill leader. Another Slovenian Tina Maze, who has since retired, won the world title in 2015.
The men's downhill takes place Saturday on the legendary "Free Fall" course, which was dreamed up by Bernhard Russi, the Swiss two-time downhill world champion and 1972 Olympic gold medalist.
Racers access the start hut via a steel staircase before plunging from 9,317 feet to 6,692 feet down to the Salastrains plateau above St. Moritz.
Switzerland's Patrick Kung is the defending champion, but Italy's Peter Fill won the 2015-16 World Cup title and leads the standings this season.
Norway's Kjetil Jansrud and Italian Dominik Paris, the winner in Kitzbuhel, are second and third in the World Cup standings.
Former world junior champion Beat Feuz triumphed at St. Moritz last year and the 29-year-old Swiss skier could improve on his World Championship bronze from Beaver Creek in 2015.
The men's slalom on February 19 is likely to be a shootout between Austria's Marcel Hirscher and Sweden's Henrik Kristofferson.
Hirscher, 27, has won four World Championship golds and a record five overall World Cup titles, while 22-year-old Kristofferson is last year's World Cup slalom champion.
It is worth keeping an eye on Briton Dave Ryding, who has been making waves after scoring his country's joint best result in a World Cup race with a second place in the slalom in Kitzbuhel last month. He equaled the achievement of Konrad Bartelski in a downhill in Val Gardena, Italy in 1981.
Ryding followed it up with 10th in the Schladming night slalom and sits fifth in the World Cup slalom standings.
Britain has won 11 medals at the World Championships but none since 1936.