Boylston Street memorial

By Erika Mahoney

April 21, 2013 Updated Apr 22, 2013 at 8:25 AM EST

Boston, MA (WBNG Binghamton) As investigators continue collecting evidence to find a motive for the Boston bombings, people are not forgetting about the victims.

Four people are dead from the violence at the Boston Marathon and the aftermath that followed in Watertown, Massachusetts.

Those four include Martin Richard, 8, Lu Lingzi, 23, Krystle Campbell, 29, and Massachusetts Institute of Technology Officer Sean Collier, 26.

On Sunday, crowds visited a memorial on Boylston Street.

Flowers, posters and American flags line the street as people come to pay their respects for the four who were killed and the 176 people who were injured.