One Boston Day will be observed in the city next Saturday, April 15— the fourth anniversary of the bombings that killed three and maimed scores of spectators and runners at the Boston Marathon in 2013. The annual commemoration was declared in 2015.

In Dorchester, home to the Richard family which lost their son and brother Martin,8, hundreds of volunteers are expected to spend the day cleaning up sites across the neighborhood.

In a statement on its website, the Martin Richard Foundation announced: “Inspired by Martin’s love of neighborhood clean-up day with the Ashmont-Adams Neighborhood Association, the Martin Richard Foundation will hold our annual community-wide One Boston Day of Service along Dorchester Avenue from 11 a.m.-2 p.m. Additional project sites include meaningful locations such as the Boys and Girls Club of Dorchester, Ryan Playground, Savin Hill Beach and the Mather School.

“Our afternoon of service will conclude with a Moment of Silence at 2:49 p.m. around the Peabody Square clock to remember Martin, Lingzi Lu, Krystle Campbell, Sean Collier and Dennis Simmonds. We will close the afternoon in gratitude and appreciation for our neighbors, friends and supporters with refreshments and treats on the T Plaza. All are welcome to attend.”

Volunteers can sign up online at teammr8.org/onebostonday. All children under 12 years old should be accompanied by an adult or older family member.