KSI and Bebe Rexha lead tributes for Oliver Tree

KSI has shared an emotional tribute to US singer-songwriter Oliver Tree, who was killed in a mid-air crash between two helicopters in Brazil, according to local reports.

Tree collaborated with YouTuber KSI on the track Voices.

Taking to X, KSI expressed his grief, writing: "Can't believe I'm actually having to type this. You're 32 man. You should still be here. You still had so much life to live. So much music to make. So much content to make. You're a legend and will always be a legend. Still doesn't feel real. Genuinely feel sick. I love you bro."

The two helicopters collided over Rio de Janeiro on Sunday morning, killing all six people on board. Tree was listed on the passenger manifest of one of the aircraft, which crashed into a car dealership in the city's western zone.

"I'm in shock," Bebe Rexha wrote via X. "I was in the middle of my CD signing in NYC when I found the news of Oliver Tree. I can't believe it. We recorded a record together to be on Dirty Blonde. He was so smart. Passionate. Talented. Kind. I'm so sad. May he rest in peace."

Tree was only weeks into his ambitious World's First World Tour, which was set to see him perform on all seven continents.

His tour schedule included more than 70 shows across 30 countries, with upcoming UK dates in Glasgow, Manchester and London slated for September.