Harrowing video shows one of the helicopters involved in the mid-air collision that killed American singer Oliver Tree hurtling toward the ground in Brazil — as a witness claimed he saw someone jumping from one of the stricken choppers.

The footage released by Rio de Janeiro’s fire department shows one of the aircraft falling uncontrollably near an electric car lot on Sunday morning, sparking a fire that set 20 vehicles ablaze.

Six people, including the quirky “Alien Boy” artist, were killed — with one seen jumping from one of the helicopters before both hit the ground, according to witness Fernandes de Freitas.

“It was terrifying, absolutely horrifying,” said the tire-repair workman.

The cause of the crash remains unknown, with the devastation of the crash scene making it hard to evaluate.

“Parts of the aircraft are scattered hundreds of meters away, so the information we have is still very preliminary,” said fire service spokesperson Fabio Contreiras.

“We really need to get the recordings and videos to understand exactly what happened.”

Oliver Tree, from Santa Cruz, California, was killed alongside Argentinian influencer Gaspar Prim, passengers Lucas Vignale and Lucas Brito Chaves, and pilot Alexandre Souza. 

The helicopter Tree was on – a  Bell 206B JetRanger III – crashed into a PR-DJJ aircraft 300 feet above Recreio dos Bandeirantes.

Charles Marsillac, 60, was the sole pilot on the other helicopter. He described himself as a “helicopter pilot” and a composer on his social media, the Brazilian outlet O’Globo reported.

“Taking new flights,” he wrote on his social media bio.

The singer, who has over 11 million monthly listeners on Spotify, was just four gigs into his global “World’s First World Tour” when he was killed.

He performed in Sao Paulo on June 6 and was set to perform across the US, Europe, Australia, and China before the end of the year.

His ex-girlfriend Melanie Martinez revealed she has been “an absolute wreck” after the artist was confirmed to be among the victims.

“It’s really hard to understand how someone who you once shared such a specific and formative time of your life with can all of a sudden be gone. He was so dedicated to his art which I admired and respected so deeply,” she said.

“Rest in peace Oliver. I know you’re making the angels giggle. I’ll be here wondering what stunt and creative project you’re scheming up in heaven. All my love.”

With Post wires.