Children sign 'I am Ali' banner at event in Louisville, Kentucky

LOUISVILLE, Ky. – Fans continued to honor boxing legend Muhammad Ali Wednesday at an "I am Ali" event in Louisville, Kentucky, which was aimed primarily at children.

People who attended the event signed a huge banner, which had the words "I am Ali" written across it.

Meanwhile, the city's mayor said all 15,000 tickets for Ali's memorial service on Friday are gone.

The box office that was handing out the tickets on a first come, first served basis opened at 10 a.m. Wednesday, but the mayor said people began lining up overnight.

The tickets were gone within 20 minutes. Some people were scalping the tickets online, although many of the postings were quickly flagged and removed.

There are still tickets available for Thursday's Islamic prayer service.

Organizers of the "I am Ali" event said the primary purpose was to let children be a part of history and to learn more about what Ali accomplished in his life, and also to inspire them by showing them what someone from their hometown meant to the entire world.

"I want that to mean, 'Never give up,' and no matter who tells you, 'You can't, you poor you' -- you always try and never give up," day care counselor Candice Stafford said.

The mayor did not have an estimate of how many people are expected to arrive in the city for Thursday's and Friday's events, but the city has partnered with federal authorities to keep the crowds under control.