New York: It's a race to the top - well, to the 86th floor, anyway. People from around the world are taking part in a vertical race up the Empire State Building. That's a total of 1,576 steps, starting at the lobby and finishing at the observation deck.
More than 600 people are registered for the annual Empire State Building Run-up, including some world-class elite athletes. Seven-time champion Thomas Dold of Germany is going for his eighth victory in a row.
Among the women, four-time winner Cindy Harris of the United States will be taking part, as well three-time winner Suzy Walsham of Australia. The event is put on by the New York Road Runners, which also hosts the annual New York City Marathon.
Like the marathon, start times are staggered. The elite men and woman start before the general field, and participants in the general field are released one at a time several seconds apart to avoid crowding.
The Empire State Building race is among the more high-profile tower climbs in the world. Participants are coming from around the United States, as well as countries including Belgium, Japan and Papua New Guinea.