BOSTON (CBS/AP) — 23,181 runners left Hopkinton Monday morning with the goal of finishing the 117th Boston Marathon. Many of them did, but there were just two winners.

Rita Jeptoo of Kenya and Lelisa Desisa Benti of Ethiopia, winners of the 117th Boston Marathon on April 15, 2013. (Photo by Jim Rogash/Getty Images)
Race day got started with 26 seconds of silence in honor of the victims of the Sandy Hook Elementary School shooting. A little more than 2 hours later, the lead runners passed the Mile 26 marker, which was decorated with the Newtown, Conn., seal and dedicated to the memory of those killed there.
The 53 wheelchair competitors left Hopkinton at 9:17 a.m., followed 15 minutes later by the 51 elite women. The men were under way at 10 a.m., followed by three waves that over the next 40 minutes sent the entire field on its way to Copley Square.

To those who doubt the accuracy of telling time using the sun's azimuth and the shadow angle of a vertical object.......this is one of the calibration / proof. Carlos took a snapshot in front of the clock at 17:26 pm. The surveyors in our group did and checked the computations.
The time recorded by the shadows allow us to verify whether photo has been composed from several shots taken at different times. Accuracy depends on the quality and number of shadows that can be used for the computations.
BP and a number of regulatory agencies had been found to adulterate (doctor) their "supposedly single shot" photos with deceitful intent. Since these still photo-op sessions (stationary posing rather than actual field emergency situation) could not have been organised by the "terrorists"(before and after the actual bombing itself), it stands to reason they could not have acted in isolation; if indeed they were guilty in setting off the bomb. Obviously the puppet-masters would want the "runners on the ground" dead to break the criminal trail leading to them.

Iconic victim who supposedly lost both legs in the Boston Marathon Bombing (BMB) was not present at the 1st explosion location. This is a conspiracy FACT. BMB was a staged inside job with high level collusion in govt.