Bolt pulls up injured in final race of career

Usain Bolt pulled up with injury on the anchor leg of the 4×100 meters relay final at the World Athletics Championships on Saturday as the last race of his unparalleled career ended in high drama.
Britain beat the United States (U.S.) for a shock gold medal.
Bolt, who had to settle for bronze in the individual 100 meters, had been hoping to sign off from the sport by leading Jamaica to a fifth successive relay gold but they were already struggling in third when he collected the baton.
The 30-year-old had taken the baton for Jamaica a few meters adrift when, straining hard to catch the leaders, he suddenly suffered a hamstring injury, began hobbling and ended up coming to a halt after doing a forward roll on the track.
As Britain went on to win gold, Bolt was tended to with his head in hands.
After a short while, though, he rose gingerly to his feet and limped across the line to huge cheers from the 56,000 crowd
The United States, with individual gold and silver medalists Justin Gatlin and Christian Coleman running the second and fourth legs, had been expected to push the Jamaicans all the way.
Instead, a brilliantly executed race by Chijindu Ujah, Adam Gemili, Danny Talbot and Nethaneel Mitchell-Blake gave Britain gold in 37.47 seconds, the best time in the world this year.
The U.S. took silver in 37.52 with Japan third in 38.04.