A heartbreaking memorial began to grow as a community grieved Tuesday on Washington Street in Hyde Park where a 5-year-old boy was tragically killed by a school bus that had just dropped him off to return home.

Family members speaking to multiple media outlets identified the boy as Lens Arthur.

Lens, a kindergartner at Up Academy in Dorchester, had just stepped off the bus and was returning home with his 11-year old cousin, his uncle told WHDH Channel 7.

The heartbreaking tragedy has shocked the community.

“Tonight we are grieving this heartbreaking loss,” said Boston Schools superintendent Mary Skipper in a statement.

“We extend our deepest condolences to our student’s family, school community, and all those affected by this tragedy. Our focus remains on supporting them and our school community. Our team is offering support services for any students, staff, and families.”

Wailing family members could be heard inside a home on Washington Street Tuesday morning.

Boston Mayor Michelle Wu, in a somber appearance in the neighborhood Monday evening said, “This is absolutely heartbreaking.”

“I am completely heartbroken at imagining what this family is experiencing right now.”

The fatal collision remains under investigation. Police said Monday night that the driver of the bus remained at the scene and was cooperating with authorities.

Suffolk DA Kevin Hayden called the incident “incredibly tragic.”

“The loss of a child at such a young age is terrible,” he said at the scene of the crash as investigators continued to work.

“These are extraordinarily complex investigations involving accident reconstruction, involving a lot of information, regarding video tape evidence, GPS evidence, and obviously what witnesses have seen and heard,” Hayden said.

Skipper, in a message to parents Tuesday morning emphasized that “the safety of our students and staff continues to be our highest priority.”

She continued, “We are working closely with the Boston Police to fully understand what happened and to support their ongoing investigation.”