The three boys were found with serious injuries at Tremont and Camden Streets shortly before 6 p.m., according to Boston police. Paramedics rushed the trio to an area hospital, with one suffering life-threatening injuries.
Officers were initially dispatched to reports of a person being hit by a car, but instead, they found this scene of carnage. Two of the boys had been slashed, and the suspect attacked a third but didn't stab him, police said.
Witnesses who chanced upon the aftermath described the bloody scene to NBC Boston.
"We was going to pick up my kids from after school," David Vasquez told the news outlet. "Me and their mother seen the kid laying on the floor. His shirt was full of blood. He had his shoe a little distance from him covered in blood. He kept trying to get up; we kept telling him to lay down."
Boston officers closed Tremont Street for several hours just before 8 p.m. as they investigated and cleared the scene, authorities said.
Police ask anyone with information to contact Boston homicide detectives at 617-343-4470. Anonymous tips can be made by calling 1-800-494-TIPS.
Click here to follow Daily Voice Lynn and receive free news updates.