An 8-month-old boy who, investigators say, was seriously injured at the hands of his mother who is also facing murder charges in the deaths of his two siblings, has died, the Plymouth County District Attorney's Office said. RELATED VIDEO ABOVE: Hundreds attend prayer vigil for Duxbury familyLindsay Clancy, 32, is accused of killing her 5-year-old daughter, Cora Clancy, and 3-year-old son, Dawson Clancy, in their Summer Street home Tuesday night. Her 8-month-old son, Callan, was injured and flown to a Boston area hospital, where he died Friday morning.“(Friday), at approximately 12:30 p.m., The state Office of the Chief Medical Examiner contacted Massachusetts State Police assigned to our office to report that at 11:18 a.m. (Friday), the third Clancy child was pronounced deceased at Children’s Hospital in Boston,” District Attorney spokeswoman Beth Stone said in a statement.First responders rushed to the home at 47 Summer St. in Duxbury just after 6 p.m. Tuesday after receiving a 911 call from Lindsay Clancy's husband. Plymouth County District Attorney Tim Cruz said the man reported the attempted suicide of his wife, who had jumped out of a window in the home. According to Cruz, first responders discovered the three children unconscious inside the home with obvious signs of trauma. Cruz would not say where in the home the children were found.The South Shore mother, who investigators said Wednesday will be charged with two counts of murder and three counts each of strangulation and assault and battery with a deadly weapon, jumped out of a window of the Duxbury home and remains hospitalized in police custody."As soon as able, we will be arraigning her on the two charges of murder in the death of her children," Cruz said.Cruz said the chief medical examiner's office will ultimately determine the manner and means of the death of the children."This is an unimaginable, senseless tragedy, and it is an ongoing investigation," Cruz said. Authorities would not comment on whether any mental illness may have played a role in the homicides or if there was any mental health history.A spokesperson for Massachusetts General Hospital confirmed Clancy is an employee."Duxbury police detectives, along with the state police detectives that are working nonstop and will continue in the days, weeks, months, or whatever it takes to get answers," Duxbury police chief Michael Carbone said.If you or someone you know is struggling with suicidal thoughts or mental health matters, please call the Suicide & Crisis Lifeline at 988 or 800-273-8255 to connect with a trained counselor, or visit 988lifeline.org.