12:13 Update: Wesley Korir wins the men's race with a time of 12:12:40. A Kenyan sweep on the podium. American Jason Hartmann takes fourth.
12:12 Update: Wesley Korir's brother was killed by a black mamba snake. Korir has started a foundation to raise money to build a medical center in his hometown for future emergency treatments.
12:10 Update: Levy Metabo caught from behind by Wesley Korir, who is now pulling away before the finish.
12:04 Update: Sharon Cherop wins the women's race with a time of 2:31:50.
12:02 Update: Sharon Cherop separates and pulls away around the turn onto Boylston Street, but Sumgong turns it back on near the finish.
12:00 Update: The two leading women, Sharon Cherop and Jemima Jelaget Sumgong, have passed mile 25 and are still stride for stride with 800 meters to go.
11:55 Update: The women's winner gets $150,000. Second place gets half that. Levy Metabo takes a comfortable lead for the men. If things hold, it's looking like there will be a Kenyan sweep.
11:52 Update: Two women are vying for the lead just after Coolidge Corner, Sharon Cherop and Jemima Jelaget Sumgong. The temperature is now 82 degrees. The women have slowed eight minutes off of last year's pace.
11:48 Update: Last year's winner Geoffrey Mutai drops out due to cramps at mile 18 and Levy Metabo takes the lead on the men's side.
The Boston Marathon began this morning with warnings for inexperienced runners to avoid participating due to excessive heat. Temperatures approached a warmer-than-normal 80 degrees this morning, and race organizers offered people the chance to drop out and race in next year's event. Some opted not to run, but many stayed in and promised to carefully watch their hydration. “You've got to know your own body,” Mike Buenting of Minneapolis told the LA Times as he waited for the starting gun. “You have to know how to hydrate and the rest will take care of itself.”