He won a singles medal in luge, taking the silver.
No American had medaled in men's singles luge since the event's introduction to the Olympics in 1964, but Mazdzer sat in fourth place after Saturday's two runs at the PyeongChang Games.
Loch's loss translated into big gains for Mazdzer and Gleirscher, who beat out the American by just over two hundredths of a second to become the first Austrian to win the event in five decades.
Team USA is starting to gain momentum in the medal hunt at the 2018 Winter Olympics. Instead of winning his third gold medal in a row in men's singles luge, and matching fellow German Georg Hackl as the only man to win three straight golds, Loch faltered on the final run of the night, falling to fifth place as Austria's David Gleirscher pulled off a thrilling upset over one of luge's all-time greats.
As an 18-year-old, West had finished 22nd in the luge men's singles at the 2014 Olympics in Sochi, Russia.
Flu blamed for 1 child's death, suspected in another
Schuchat also revealed that one in every 10 people who died in the US last week had suffered flu-like symptoms. Influenza activity is breaking recent records this season, and is not yet slowing down, according to the CDC.
Gleirscher's cumulative time over four runs (Runs 1 and 2 took place on Saturday, with Runs 3 and 4 on Sunday) was 3:10.702, as he won by 0.026 over Mazdzer. Mazdzer had previously never finished better than 13th at the winter Olympics.
On Sunday, he'll try to win a historic medal for Team U.S.A using the same technique that has proven effective for him so far.
The leader going into the final run was two-time defending gold medalist Felix Loch of Germany, who was looking to equal the record of his countryman, George Hackl, who finished first in 1992, '94 and '98. Germany's Johannes Ludwig rounded out the podium with a time of 3:10.932.
"Hi everyone this is USA luge racer Chris Mazdzer ok bye", Buzzfeed reporter David Muck brought Mazbdzer's good looks to the internet's attention on Saturday.