This wasn't supposed to be how it ended.
What should have been a triumphant finish to a momentous career ended in injury when Usain Bolt fell to the track in the midst of his last-ever race at the IAAF World Championships in London on Saturday.
Bolt had apparently developed a cramp in his left hamstring just after taking the baton in his anchor leg of the 4x100 relay and was unable to finish.
The United Kingdom went on to win the race, and America and Japan took second and third as Bolt's teammates helped him limp off of the track. Read more...More about Usain Bolt, Entertainment, and Sports