BOSTON -- Four-time Olympian Shalane Flanagan has dropped out of the Boston Marathon with a back injury.
The native of nearby Marblehead posted the fastest time ever for an American woman on the course in 2014. She finished sixth in the Olympic marathon in Rio de Janeiro last summer and won a bronze medal at the 2008 Summer Games in the 10,000 meters.
Flanagan says Boston is her favorite race and she's "extremely sad'' she won't be able to run it on April 17 for a fourth time.
The Boston Athletic Association says the injury will take four to six weeks to heal.
Also Tuesday, five-time Japanese record-holder Suguru Osako was added to the Boston field. It will be his marathon debut.