US sprinter Manteo Mitchell suffered a broken leg when running for his team in Thursday\'s Olympic Games 4x400m relay semi-final, but still managed to finish his lap. The US team finished second to the Bahamas in the heat in identical times of 2:58.87, the fastest time ever run in the first round of the relay at the Olympics. The 25-year-old Mitchell had slipped on a stairway in the Olympic Village earlier this week, and that misfortune reared its head after just 100 metres of his one-lap run. \"Three days ago I was going up the stairs and I kind of missed one and landed awkwardly,\" Mitchell said. \"I got treatment and I was fine. I did workouts, and when I warmed up today I felt really well. I felt I could go 44 (seconds)-low. \"I got out pretty slow, but I picked it up and when I got to the 100m mark it felt weird. I was thinking I just didn\'t feel right. As soon as I took the first step past the 200m mark, I felt it break.\" Mitchell added: \"I heard it. I even put out a little war cry, but the crowd was so loud you couldn\'t hear it. I wanted to just lie down. It felt like somebody literally just snapped my leg in half. \"I knew if I finished strong we could still get it (the baton) around. I saw Josh Mance motioning me in for me to hand it off to him, which lifted me. I didn\'t want to let those three guys down, or the team down, so I just ran on it. It hurt so bad. I\'m pretty amazed that I still split 45 seconds on a broken leg.\" After the race, Mitchell was taken to the Athlete Village medical area, where his leg was x-rayed and diagnosed by team doctor Bob Adams as a break of his left fibula bone. Team USA will announce the final line-up for the men\'s 4x400m final on Friday.