2008 Boston Marathon

Men's elite runners cross the start line of the 112th Boston Marathon, Monday, April 21, 2008, in Hopkinton, Mass. More than 25,000 runners participated in today's race.

Joan Benoit Samuelson, two-time Boston Marathon winner and 1984 Olympic gold medalist, prepares to fire the start gun for the women's race of the 112th Boston Marathon, Monday, April 21, 2008 in Hopkinton, Mass. More than 25,000 runners participated in the race.

Sen. John Kerry, D-Mass., prepares to fire the start gun for the wheelchair race of the 112th Boston Marathon, Monday, April 21, 2008 in Hopkinton, Mass.

Runners in the 112th Boston Marathon round a curve and climb a hill near the 1 mile marker in Hopkinton, Mass., on Monday, April 21, 2008.

Lance Armstrong, center, crosses the start line of the 112th Boston Marathon, Monday, April 21, 2008, in Hopkinton, Mass.

Dick, rear, and Rick Hoyt climb a hill near the 1 mile marker of the 112th Boston Marathon in Hopkinton, Mass., on Monday, April 21, 2008. This year marks the 26th time that Team Hoyt has run in the Boston Marathon.

Robert Cheruiyot, of Kenya, is silhouetted as he runs under a traffic bridge with less than a mile to go in the 112th running of the 26.2 mile Boston Marathon in Boston, Monday, April 21, 2008. Cheruiyot went on to win the race with a time of 2:07:46.

Robert Cheruiyot of Kenya gestures as he approaches the tape to win the 112th Boston Marathon in Boston Monday, April 21, 2008. The win was Cheruiyot's fourth in Boston.

Dire Tune of Ethiopia raises her arms as she breaks the tape to win the women's division of the Boston Marathon in Boston, Monday April 21, 2008.

Wakako Tsuchida of Japan hits the tape to win the women's wheelchair division of the 112th Boston Marathon in Boston Monday, April 21, 2008.

Robert Cheruiyot of Kenya, right, and Dire Tune of Ethiopia, left, wave to spectators after winning the Boston Marathon in Boston, Monday, April 21, 2008.

Ernst Van Dyk of South Africa holds up his trophy after winning the men's wheelchair division of the Boston Marathon in Boston, Monday April 21, 2008.

Lance Armstrong, seven-time Tour de France winner and cancer survivor, warms up prior to the start of the 112th Boston Marathon, Monday, April 21, 2008, in Hopkinton, Mass. More than 25,000 runners participated in the race.

The 112th Boston Marathon runners rest up in the Hopkinton, Mass., Athlete's Village, before the start of the race, Monday, April 21, 2008.

The top three finishers in the U.S. women's Olympic Marathon Trials in Boston, Magdalena Lewy-Boulet, left, Deena Kastor, center, and Blake Russell, pose with a torch near the start line of the 112th Boston Marathon, Monday, April 21, 2008, in Hopkinton, Mass. Lewy-Boulet, Kastor, and Russell will represent the U.S. in the 2008 Olympics in Beijing.