A selfless act of kindness by Westfield High School Principal Derrick Nelson to donate bone marrow to a 14-year-old boy in France led to the monthlong coma that ultimately took his life Monday, according to his family.

Nelson, 44, underwent the donation procedure at a Bergen County hospital in February, his 81-year-old father Willie Nelson said Tuesday in an interview with NJ Advance Media.

“After the procedure he did, he couldn’t speak and was lying in the bed,” his father, 81, said. “His eyes were open and he realized who we were. But he couldn’t move. He never spoke again.”

Nelson said he and his wife, Juanita, also 81, his son’s fiancé, Sheronda, and the couple’s 5-year-old daughter kept vigil at his room at Hackensack University Hospital for weeks, hoping he would recover. Nelson died Sunday.

“We really don’t know the full story of what happened,” Willie Nelson said. “We were expecting him to come out of the coma he was in. But he didn’t make it.”

Derrick Nelson talked about his desire to help the teen in France during an interview with the Westfield High School student newspaper hiseye.org just before the surgery.

“If it’s just a little bit of pain for a little bit of time that can give someone years of joy, it’s all worth it,” Nelson told the student newspaper. The bone marrow would provide stem cells that could help the teen, he said, though the boy’s ailment was not disclosed.

Nelson also detailed how the donation match occurred, and some complications that delayed the surgery.

Nelson told hiseye.org that he suffered from sleep apnea and that doctors were concerned about using anesthesia. A plan to harvest stem cells intravenously was also scrapped when doctors learned Nelson was a carrier for sickle cell anemia. They ultimately decided to do the bone marrow surgery under a local anesthetic, Nelson told the student newspaper.

Nelson’s father said he informed school officials that he would need time off work to recover from the procedure.

Salm Sivaad, a musician from Atlanta, Georgia, tweeted that his friend had died trying to help save the life of a person he did not know.

“It turns out Derrick’s death was no less heroic, and ultimately tragic,” Sivaad tweeted. “My friend died trying to save the life of a child...a total stranger who he’d never met from a foreign land.”

(3) It turns out Derrick’s death was no less heroic, and ultimately tragic. My friend died trying to save the life of a child...a total stranger who he’d never met from a foreign land. Derrick died as a result of complications while donating life-saving bone marrow. — Salim Sivaad (@SalimSivaad) April 9, 2019

At Westfield High School on Tuesday, students recalled the beloved principal for his selfless act and compassion.

"I always knew that he was a great man. He was the type of man that used authority but was still such an approachable man. I can’t name a single person that didn’t like him,” said Marcela Avans a 16-year-old junior at Westfield High School. “When I found out that he was first ill, it broke my heart because he was helping someone, but it really made me respect him and appreciate his service to the community even more.”

Emma Roth, a 17-year-old junior, said Nelson brought a tremendous energy for his role at Westfield High School.

“I just always remember him with a smile on his face at the games and he was very energetic," Roth said. “He was different from any other principal I’ve ever had.”

Nelson’s grieving parents said they plan to have a funeral later this week at St. John’s Baptist Church in Scotch Plains. They said they would try to finalize and announce services later Tuesday.

Nelson served as an officer in the U.S. Army Reserve for more than 20 years and had recently re-enlisted, his father said. His military service included an assignment in the Middle East, school officials have said.

Westfield High School Principal Derrick Nelson died on April 7. (NJ.com file photo)

Before coming to Westfield, Nelson served as assistant principal in two public schools in Orange and he began his career in education in 2002 as a teacher in the Plainfield School District.

There was a huge outpouring of grief on social media after news of Nelson’s death broke Monday with many recalling his generous spirit, immense character and kindness.

“Dr. Nelson touched us all with his kindness, compassion, integrity, and endlessly positive attitude,” Westfield School District Superintendent Dr. Margaret Dolan said in a letter to parents on Monday.

Dolan said counselors would be available beginning at 8 a.m. Tuesday for Westfield High School students.

“He was the type of guy to take the shirt off his back and give it to you,” his father said. “He was very good at everything he did. He gave 100 percent of his life to education.”

Reporter Taylor Tiamoyo Harris contributed to this report.

Editor’s note: This story has been edited to correct the date of Dr. Nelson’s death and the age of his daughter.

Anthony G. Attrino may be reached at tattrino@njadvancemedia.com. Follow him on Twitter @TonyAttrino. Find NJ.com on Facebook.

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