116th Boston Marathon

Volunteers prepare cups of water for runners at the start of the 116th running of the Boston Marathon April 16, 2012 in Hopkinton, Massachusetts. (Photo by Darren McCollester/Getty Images)

116th Boston Marathon

(Photo by Darren McCollester/Getty Images)

Runners head out at the start of the 116th running of the Boston Marathon April 16, 2012 in Hopkinton, Massachusetts. (Photo by Darren McCollester/Getty Images)

116th Boston Marathon

Runners head out at the start of the 116th running of the Boston Marathon April 16, 2012 in Hopkinton, Massachusetts. (Photo by Darren McCollester/Getty Images)

116th Boston Marathon

Runners head out during the start of the 116th running of the Boston Marathon April 16, 2012 in Hopkinton, Massachusetts. (Photo by Darren McCollester/Getty Images)

116th Boston Marathon

Children slap high fives with passing runners at the start of the 116th running of the Boston Marathon April 16, 2012 in Hopkinton, Massachusetts. (Photo by Darren McCollester/Getty Images)

116th Boston Marathon

Runners head out during the start of the 116th running of the Boston Marathon April 16, 2012 in Hopkinton, Massachusetts. (Photo by Darren McCollester/Getty Images)

116th Boston Marathon

Men head out during the start of the 116th running of the Boston Marathon April 16, 2012 in Hopkinton, Massachusetts. (Photo by Darren McCollester/Getty Images)

116th Boston Marathon

Runners head out at the start of the 116th running of the Boston Marathon April 16, 2012 in Hopkinton, Massachusetts. (Photo by Darren McCollester/Getty Images)

116th Boston Marathon

(Photo by Darren McCollester/Getty Images)

Runners take water from volunteers during the start of the 116th running of the Boston Marathon April 16, 2012 in Hopkinton, Massachusetts. (Photo by Darren McCollester/Getty Images)

116th Boston Marathon

Crossing the Finish Line (credit: Nick Darling)

116th Boston Marathon

Crossing the Finish Line (credit: Nick Darling)