City Honors Victims of Boston Marathon, Salutes Emergency Workers

Roses hang on a lamp post near the site of the second bomb blast on the one-year anniversary of the Boston Marathon bombings iN Massachusetts, April 15, 2014.

Kevin Brown puts up a handmade memorial for victims of the 2013 Boston Marathon bombings near the race's finish line in Massachusetts, April 15, 2014.

Family members of the victims of the 2013 Boston Marathon bombings are joined by Massachusetts Governor Deval Patrick (wearing a baseball cap, left) and Boston Mayor Marty Walsh (3rd right) as they walk to the finish line, April 15, 2014.

Security personnel walk across the Boston Marathon finish line prior to a remembrance ceremony for family members and survivors of the 2013 Boston Marathon bombing, on Boylston Street, April 15, 2014.

Police on bikes cycle across the Boston Marathon finish line prior to a remembrance ceremony for family members and survivors of the 2013 Boston Marathon bombings on Boylston Street, April 15, 2014.

A law enforcement official searches a man near the finish line of the Boston Marathon in anticipation of the arrival of Vice President Joe Biden, April 15, 2014.

These photos were taken April 15, 2013 and April 14, 2014. The 2013 photo shows medical workers aiding injured people on Boylston Street near the finish line of the 2013 Boston Marathon following two bomb explosions, and nearly a year later traffic flowing on the same street.

These photos were taken April 15, 2013 and April 14, 2014. The photo from 2013 shows medical workers aiding injured people along Boylston Street after the first of two bombs exploded near the finish line of the 2013 Boston Marathon.