PHOTOS: Special Olympics Opening Ceremony In Los Angeles

LOS ANGELES (AP/FOX 11) -- The Special Olympic World Games kicked off Saturday in Los Angeles as 6,500 athletes from 165 countries streamed into the Memorial Coliseum to cheers and roars.

The athletes will participate in 25 sports over nine days, ranging from weightlifting to the triathlon. Applause greeted the athletes, including a tiny contingent from Afghanistan.

It was the largest gathering of athletes in Los Angeles since the 1984 Summer Olympics.

First lady Michelle Obama was to deliver the opening message, followed by musical performances by Avril Lavigne, Stevie Wonder, Colombian reggaeton artist J Balvin and others.

Late-night television talk show host Jimmy Kimmel thanked the competitors and the international crowd of spectators for coming and joked about California's long drought, saying he hoped they brought water.

"That Olympic flame they're going to light will truly burn forever because we don't have the water to put it out," Kimmel said.

Kimmel also praised the athletes. "You remind me of how deeply lazy a man I am," he said.

Emmy Award-winning choreographer Debbie Allen is directing the three-hour program being broadcast live by ESPN.

The real stars of the show, however, were expected to be the athletes.

"There's no greater global stage than Los Angeles to create the awareness that leads to acceptance and inclusion of people with intellectual disabilities," said Patrick McClenahan, president and CEO of LA2015, the nonprofit group that brought the Special Olympics back to Los Angeles for the first time since 1972.

McClenahan is a veteran broadcast executive and father of a daughter with autism.

For information on the games and activities go to www.LA2015.org

RELATED: All of FOX 11's coverage of the Special Olympics World Games can be found here.

The competition is open to athletes 8 years or older with intellectual disabilities that result in certain limitations in cognitive function and other skills. To reach the world stage, participants must take part in a sanctioned regional competition.

This week, they are being welcomed to Los Angeles by an all-star lineup of gold medalists from the traditional Olympics, including swimmer Michael Phelps, diver Greg Louganis and decathlon champ Rafer Johnson. The latter helped organize the first Special Olympics World Games in Chicago in 1968.

The games were the brainchild of President John Kennedy's sister Eunice Kennedy Shriver, who held informal backyard competitions at her home before deciding to take the competition international in 1968. She said she believed everybody should have a chance to feel special.