Danny Nickerson has died after a battle with cancer, bringing a tragic end to the story of a boy whose wish for birthday cards went viral and led to hundreds of thousands of people joining his cause.

Six-year-old Nickerson passed away on Friday, family members confirmed.

The boy’s mother shared the devastating news on a Facebook page dedicated to health updates, called Danny’s Warriors:

“Unfortunately there’s no such thing as privacy and respect for feelings anymore. I was waiting to make sure all members of our family knew before I broadcasted it to the world.

My precious sweet boy earned his angel wings earlier this afternoon after a courageous 18 month battle. Our lord came and carried his body to heaven. His body was so tired of fighting. He is now cancer free and running and playing and laughing with God and all of the other precious children.

Prayers are needed for all of us right now. Please surround us in your prayers.”

The boy became famous last year when he wished for a birthday card to celebrate turning 6 on July 25. His story spread quickly and led to the viral hashtags #CardsForDanny and #HappyBirthdayDanny.

As the story spread, many people joined in on the young boy’s cause. Danny Nickerson even got an invite from New England Patriots owner Robert Kraft to see the team practice. When he showed up, Danny got another birthday gift — a Patriots jersey with “Danny” on the back and the number “6.”

“He’s having an absolute blast with everything,” his father, Daniel Jamieson, told WCVB. “He’s been smiling so much the last few week. It’s been absolutely beautiful.”

Nickerson’s aunt Gail Chamberlin told CNN that the 8,000 boxes of mail the family received from around the world was “a blessing … [it] gives Daniel something to look forward to each day.”

But Danny’s health had taken a turn in the last day. On Thursday, his mother posted a frightening healthy update:

“This morning was by far the most terrifying morning I’ve ever had in my life. I woke up at 5:46 to find Danny laying next to me rapidly breathing, boiling hot and completely unresponsive. I couldn’t wake him up. We were taken by ambulance to Boston children’s hospital. By the time we reached the hospital his temperature had returned to normal. After a few hours finally came around and woke up and was alert. We were able to get some medicine into him to make him comfortable. His stomach was still bothering him and causing him a lot of distress. They gave him a few treatments.”

With news that Danny Nickerson died spreading, many who were touched by his story are now reaching out to the family yet again, with the Danny’s Warriors page filled with condolences.

[Image via Facebook]