After a few seconds he got up and continued the race.
Derek's dad came to him and helped him. Derek's dad walked some of the way, but then let him go, so Derek could finish the race on his own.
When Derek crossed the finish line he got an ovation from 65,00 people.
Derek said, "if you don't give up you cant fail."
Through the determination of this amazing athlete, it just goes to show that anything is possible.