Stacy and Bill Halstead and their son, Tripp, in their Jefferson, Ga., home in July 2013. Tripp died Thursday at age 7, more than five years after a tree limb fell on his head, leaving him with brain damage and paralyzed. (Atlanta Journal-Constitution/Phil Skinner)

Tripp Halstead was struggling to breathe. The 7-year-old boy’s heart was beating fast when his mother went to wake him up for school on Thursday morning.

It could be pneumonia, doctors told Stacy Halstead. They recommended bronchial washing, a procedure in which a thin, fiber-optic bronchoscope is inserted through the nose or mouth and into the lungs to find infections, Halstead wrote on Facebook, as she has done so for years. She shared a picture of her son asleep in a hospital bed next to his stuffed monkey, an oxygen mask covering his tiny face.

Chronicling her son’s life has been a form of therapy, the Georgia mother once said. It allowed her to be inspired and to inspire hundreds of thousands of strangers as her son fought to survive since his accident in the fall of 2012.

Trippadoo, as his mother fondly calls him, had been fighting for 5½ years. On Thursday, he couldn’t fight anymore. “His little body was just done fighting this last infection,” Halstead wrote. “His little heart gave out.”

Tripp Hughes Halstead died at 5:47 p.m.

Tripp had lived most of his short life paralyzed and unable to say anything other than groans and whimpers. He was 2 when the near-fatal accident happened on Oct. 29, 2012. He was playing under a tree outside his day-care center on that warm, fall day when a large limb fell on his head, crushing his skull. He was airlifted to a hospital in Atlanta, and his parents were warned that he might not survive. But the small boy with spiked brown hair did survive, as announced by his mother in a euphoric social media post with all caps and exclamation points.

The accident severely damaged Tripp’s frontal and parietal lobes, areas of the brain that control cognitive and motor functions, CNN reported in 2013. Gone was the toddler who used to flash a wide grin for pictures, blow kisses, ride his red bike and say he loves his dad “to the moon.”

He couldn’t move his head up; his eyes were trapped in an expressionless stare, even as his long lashes blinked. His arms and legs were completely straight, like those of a mannequin. He was living on myriad medications and spending a few days a week in physical therapy.

“If he makes eye contact with you, it’s a great day,” Halstead told NBC affiliate 11Alive last year. “Tripp is just such a good kid, you know, just so sweet and so funny,” she said, her voice trembling. Then she shrugged her shoulders. “And they don’t know whether that will come back.”

Pictures that Halstead shared on Facebook in recent years, and even in the last months, showed a boy still paralyzed but with a smile on his face.

Tripp’s story has drawn a massive following that has grown to 1.3 million Facebook followers. For more than five years, complete strangers followed Tripp’s journey as he went to school for the first time and slowly showed a tiny glimmer of the cheerful boy he once was.

“You have been the most loyal and understanding followers we could have ever asked for and We thank you from the bottom of our hearts for the past 5½ years,” his parents told their readers and supporters. “You let us into your lives and You were there when we needed you most.”

The Halsteads had tried for years to conceive a child, and on Thursday, they said goodbye to the boy they had wanted for so long.

“We love you Trippadoo,” they wrote a few hours after his death, “and you will never realize the impact you made on our lives.”

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