Explosions near the finish line of the Boston Marathon shook the city on a serene Monday holiday. The top finishers had completed the race hours before the explosions, but dozens were injured in the blast.

Runners Shalane Flanagan and Kara Goucher, who finished fourth and sixth in the women's division, respectively, responded to the events.

Multiple players from the Indiana Pacers, in Boston for Tuesday's game against the Celtics (which was later canceled and will not be made up), were in attendence at Monday's running of the Boston Marathon.

The Boston Red Sox were coming off a win at Fenway Park against the Rays, a game that ended shortly before the explosions happened.

More of Boston's current and former professional athletes took to Twitter to react and express their sympathy and concern for the victims.

Join the conversation and follow us on Twitter @ESPN.

Comment »