(CNN) A Congolese boy who traveled to the United States to have a tumor removed from his face died Friday, the organization who sponsored him said in a statement.
The Dikembe Mutombo Foundation, created by the former NBA player, said in a statement on Instagram on Saturday that Matadi Sela Petit, 8, died after suffering a rare genetic reaction to anesthesia during surgery.
"Despite the diligent efforts of his medical caregivers, Matadi did not recover and he passed away last night," the statement said.
The Mutombo Foundation sponsored Matadi's trip to the United States. He arrived in Los Angeles on December 12 with his father, CNN affiliate KABC reported.
The founder and director of the Osborne Head and Neck Institute, Dr. Ryan Osborne, performed the surgery, the Mutombo Foundation said.
"We are devastated by the loss of Matadi and our heart goes out to his father, his mother and the rest of his family, and all his old and new friends," the foundation said.
The foundation added Matadi's memory "will inspire us to continue to develop efforts and partnerships to improve the lives of the children of the Democratic Republic of the Congo."
According to KABC, Mutombo met Matadi in Congo. He was treated for cleft palate repair at the hospital the foundation built in the country. However, there were no specialists to treat the tumor growing on the left side of his face.
Mutombo, who was born in the Congolese capital of Kinshasa, created his foundation in 1997 with the mission to "improve the health, education, and quality of life of life for the people in the Democratic Republic of Congo," the organization states in its website.