Martin was 8 years old when he killed on April 15, 2013, as he watched the marathon from near the finish line with his family. His mother was gravely injured, and his sister, who was 7 at the time, lost a leg.
Photos from Wednesday's ceremonial groundbreaking show children in hard hats using shovels to dig dirt. Martin's Park, located next to the Boston Children's Museum at the Smith Family Waterfront, is expected to open in the fall of 2018, according to a press release from the office of Massachusetts Gov. Charlie Baker.
"This park will bring light & hope to that darkness, honoring his memory & allowing kids to be kids," Baker wrote on Twitter.
Boston Mayor Marty Walsh wrote on Twitter that the park will remind its visitors of "hope, compassion & love."
"Martin's spirit will always live on in Boston & in Martin's Park," Walsh wrote.
Both Baker and Walsh spoke at the groundbreaking ceremony, as well as Martin's family.
Martin's sister, Jane Richard, said she knows that her brother is happy that the community is coming together.
The park will have wheelchair ramps so it is accessible to everyone, The Associated Press reported. It will also be outfitted with a pirate ship, a bucket swing and an amphitheater, according to the AP.