Transcript for Kim Jong Un's sister sits behind Vice President Mike Pence at Winter Games

survive. And taking center stage in south kree dwra. . Kim Jong-un's sister and what she did, and the fall for an American star. ABC's Matt Gutman at the winter games. Reporter: North and south Korea marched together under the same flag and hand in hand, members of the joint, north/south women's hockey team charged up to light the olympic flame. Kim Jong-un's trusted sister shaking hands with South Korea's president. She was seated right behind vice president Mike pence, but his office says he pointedly did not reach out to North Korea, and of course, the athletes. The most ever at a winter games including that huge American delegati delegation. So much hope for Nathan Chen. ABC first profiled him when he was 8 years old. Which olympics are we going to see you in? 2018. How does anybody deal with the amount of pressure Thaut you have had to deal with? It's overwhelming and you have to focus on little things that take you there. Reporter: He stumbled and even fell. Coming in fourth, but he is still the favorite for gold in the individual events. At the opening ceremony, the windchill dipped into the teens and the question, would the load athlete repeat his shirtless performance from the Rio games? The answer came out bearing a flag and everything else except for that grass skirt. That athlete was a lot hardier than the rest of us. It was broughtly cold in that stadium, but organizers handed out warming kits which included heating seating pads, blankets, beenies, and I have that fistful of hand warmers. The forecast for the next two weeks, David, a lot more cold. The hand warmers definitely better than the grass skirt. Our thanks to you tonight. There is much more ahead on

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