RIO DE JANEIRO (AP) — Officials in Brazil on Monday were inspecting the site of a crash in which six people were killed Sunday, after two helicopters collided midair over a suburb of Rio de Janeiro.

American singer Oliver Tree was among those listed on the passenger list filed with aviation authorities for one of the helicopters that crashed into the parking lot of a car dealership, although police did not yet confirm his body was found in the crash.

Police confirmed the death of Gaspar Prim Díaz — an Argentine content creator known as Gaspi with more than 2.8 million followers on YouTube — another Argentine Lucas Vignale and three Brazilians — Lucas Brito, Charles Marsillac and Alexandre Souza. The body of one foreigner was not yet identified.

Human error might have led to the collision between the two helicopters, Rio de Janeiro police investigator Alan Luxardo told reporters Monday at the crash site. He added that authorities were investigating whether air traffic controllers or one of the pilots was responsible for the crash.

Tree, 32, was visiting Rio as part of a world tour that included stops in Argentina, Brazil, Portugal and Spain. On Saturday, the singer and comedian had published a comical video where Tree was seen playing soccer in a Brazilian neighborhood.

Some celebrities began to publish tributes to Tree on Sunday, including Jake Paul, a promoter known for taking on professional boxers in highly publicized fights, who called the singer “one of the most kind and funny people in the world.”

Drew Binsky, a content creator known for visiting every country in the world, wrote on Instagram that Tree had come to him for travel advice because the singer also wanted to visit every country.

“We just spoke a few days ago and I was planning to show him around Prague in three weeks,” Binsky wrote. “He has become a great friend of mine and is genuinely one of the kindest and most positive people I’ve ever met.”

Argentine streaming channel Blender thanked Gaspi for his art in a post on X.

“Every one of us will miss you,” Blender said.

___

Follow AP’s Latin America coverage at https://apnews.com/hub/latin-america