File-Jamaica's Usain Bolt poses next to a scoreboard after winning the gold and setting a new world record in the men's 200-meter final during the athletics competitions in the National Stadium at the Beijing 2008 Olympics in Beijing, Wednesday, Aug. 20, 2008. The Olympics are remembered for the stars. That was true in Beijing in 2008, and the stars were Michael Phelps and Bolt. But Beijing is also storied for its signature venues like the “Bird's Nest” stadium, and the “Water Cube” swimming venue. No Olympics before — or since — have impacted a city the way the Olympics did Beijing. (AP Photo/Thomas Kienzle, File)

File-Usain Bolt of Jamaica, third right, reacts as he wins the men's 100-meter final with a world record in athletics competitions in the National Stadium at the Beijing 2008 Olympics in Beijing, Saturday, Aug. 16, 2008. The Olympics are remembered for the stars. That was true in Beijing in 2008, and the stars were Michael Phelps and Bolt. But Beijing is also storied for its signature venues like the “Bird's Nest” stadium, and the “Water Cube” swimming venue. No Olympics before — or since — have impacted a city the way the Olympics did Beijing. (AP Photo/Anja Niedringhaus, File)

File-Visitors walk past the National Aquatics Center, known as the Water Cube, on the eve of the one-year anniversary of the opening of the Olympic Games, in Beijing Friday, Aug. 7, 2009. The Olympics are remembered for the stars. That was true in Beijing in 2008, and the stars were Michael Phelps and Usain Bolt. But Beijing is also storied for its signature venues like the “Bird's Nest” stadium, and the “Water Cube” swimming venue. No Olympics before — or since — have impacted a city the way the Olympics did Beijing. (AP Photo/Greg Baker, File)

File-Jamaica's Usain Bolt celebrates as he wins the men's 200-meter final with a world record during the athletics competitions in the National Stadium at the Beijing 2008 Olympics in Beijing, Wednesday, Aug. 20, 2008. The Olympics are remembered for the stars. That was true in Beijing in 2008, and the stars were Michael Phelps and Bolt. But Beijing is also storied for its signature venues like the “Bird's Nest” stadium, and the “Water Cube” swimming venue. No Olympics before — or since — have impacted a city the way the Olympics did Beijing. (AP Photo/Thomas Kienzle, File)

File-United States' Michael Phelps swims to win his 8th gold medal in the men's 4x100-meter medley relay final during the swimming competitions in the National Aquatics Center at the Beijing 2008 Olympics in Beijing, Sunday, Aug. 17, 2008. The Olympics are remembered for the stars. That was true in Beijing in 2008, and the stars were Phelps and Usain Bolt. But Beijing is also storied for its signature venues like the “Bird's Nest” stadium, and the “Water Cube” swimming venue. No Olympics before — or since — have impacted a city the way the Olympics did Beijing. (AP Photo/Mark J. Terrill, File)

File-Gold medalist United States' Michael Phelps, center, reacts during the presentation ceremony for the men's 100-meter butterfly final during the swimming competitions in the National Aquatics Center at the Beijing 2008 Olympics in Beijing, Saturday, Aug. 16, 2008. At left is Serbia's Milorad Cavic, who took silver and and at right is bronze medalist Andrew Lauterstein from Australia. The Olympics are remembered for the stars. That was true in Beijing in 2008, and the stars were Phelps and Usain Bolt. But Beijing is also storied for its signature venues like the “Bird's Nest” stadium, and the “Water Cube” swimming venue. No Olympics before — or since — have impacted a city the way the Olympics did Beijing. (AP Photo/Mark Baker, File)

File- United States' Michael Phelps celebrates winning the gold in the men's 100-meter butterfly final during the swimming competitions in the National Aquatics Center at the Beijing 2008 Olympics in Beijing, Saturday, Aug. 16, 2008. The Olympics are remembered for the stars. That was true in Beijing in 2008, and the stars were Phelps and Usain Bolt. But Beijing is also storied for its signature venues like the “Bird's Nest” stadium, and the “Water Cube” swimming venue. No Olympics before — or since — have impacted a city the way the Olympics did Beijing. (AP Photo/Mark J. Terrill, File)

File- Jamaica's Usain Bolt celebrates winning his third gold medal after the men's 4x100-meter final during the athletics competitions in the National Stadium at the Beijing 2008 Olympics in Beijing, Friday, Aug. 22, 2008. The Olympics are remembered for the stars. That was true in Beijing in 2008, and the stars were Michael Phelps and Bolt. But Beijing is also storied for its signature venues like the “Bird's Nest” stadium, and the “Water Cube” swimming venue. No Olympics before — or since — have impacted a city the way the Olympics did Beijing. (AP Photo/David J. Phillip, File)

File-Participants dance under threatening skies at a gathering to watch the announcement of the 2022 Winter Olympics host city outside the Beijing Olympic Stadium, also known as the Birds Nest, in Beijing, Friday, July 31, 2015. The Olympics are remembered for the stars. That was true in Beijing in 2008, and the stars were Michael Phelps and Usain Bolt. But Beijing is also storied for its signature venues like the “Bird's Nest” stadium, and the “Water Cube” swimming venue. No Olympics before — or since — have impacted a city the way the Olympics did Beijing. (AP Photo/Mark Schiefelbein, File)

File-United States Michael Phelps swims to the gold in the men's 4x100-meter medley relay final during the swimming competitions in the National Aquatics Center at the Beijing 2008 Olympics in Beijing, Sunday, Aug. 17, 2008. The Olympics are remembered for the stars. That was true in Beijing in 2008, and the stars were Phelps and Usain Bolt. But Beijing is also storied for its signature venues like the “Bird's Nest” stadium, and the “Water Cube” swimming venue. No Olympics before — or since — have impacted a city the way the Olympics did Beijing. (AP Photo/Mark J. Terrill, File)