Police said Mark DiBona was running towards the escalator on the second floor in a Sears department store at about 6:30 p.m. Friday when the incident occurred.
Police said the boy grabbed the moving railing with both hands and was somehow pulled through a gap between the escalator and a Plexiglas barrier. Authorities said the boy then fell 18 feet onto a jewelry display case.
The boy was with members of his family and a family friend during the incident. He was taken to UMass Memorial Medical Center in Worcester where he died shortly before 10 p.m. Saturday.
The store was closed until Saturday afternoon while state and local police investigated. The escalator remains shut.
"Customer safety is our top priority at Sears," said Sears spokeswoman Kim Freely. "Our thoughts and prayers are with the victim and the family. We are fully cooperating with the police department's investigation into this unfortunate event."
State and local police were also looking into whether there were any building or escalator code violations.
The Worcester District Attorney's Office said there were no signs of foul play.