“Hallie died peacefully in her sleep on Sunday morning as Jen and I held her hands in bed,” Doug wrote. “We’re completely lost and heartbroken without Hallie. Our lives will never be the same.”

Following Hallie’s relapse, Doug wrote that the family was trying to stay positive despite the obvious obstacles in his daughter’s path.

“I’m choosing to stay positive,” the reporter said at the time.

“Hallie has beaten every single obstacle that AML has thrown her so far. This will absolutely be her toughest test, but if anyone can topple it, it’s our fierce little Hallie Bear.“

Even so, Doug admitted they that “knew the prognosis was poor when she relapsed after her bone marrow transplant, so the whole family spent special time at the hospital last week, but we held out hope for remission because of how brave, strong and resilient Hallie had been through her entire nine-month battle with acute myeloid leukemia and all of its complications.” 

As per the American Cancer Society, acute myeloid leukemia starts in the bone marrow but moves quickly into the blood. Thereafter it can spread to the lymph nodes, the liver, the spleen and central nervous system.

Speaking to the Boston Herald, Doug said that he had spent almost half his nights at Boston’s Children Hospital since his daughter’s diagnosis last year.

“My wife and I have switched off between caring for Hallie and our 5-year-old, Olivia, at home,” he explained.

Doug’s wife Jen, meanwhile, described the feeling of losing her daughter as having a hole in her heart.