More than 10,000 runners took off from Garfield Park early Sunday morning to compete in the third annual Bank of America Chicago Half Marathon on the city's West Side. Officially known as the Bank of America Chicago 13.1 — 13.1 miles being the distance of a half marathon — the race is the second of the three Bank of America Chicago Distance Series events this year, each progressing in length. The Shamrock Shuffle, an 8-kilometer run, was held in March at Grant Park. The prestigious Chicago Marathon, which covers 26.2 miles, is scheduled for Sunday, Oct. 13, also at Grant Park. The half marathon was won by Peter Njeru of Kenya in a brisk in 1 hour, 1 minute and 45 seconds.