When Malone took the stage at the KAABOO Del Mar festival north of San Diego, he wore a shirt adorned with pink, blue and orange flowers that read “RIP Mac Miller,” and his pants were decorated with hearts.
A source told PEOPLE that Miller went into cardiac arrest after an apparent drug overdose. The official cause of death is yet to be determined.
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“Malcolm McCormick, known and adored by fans as Mac Miller, has tragically passed away at the age of 26,” his family said in a statement provided to PEOPLE. “He was a bright light in this world for his family, friends and fans. Thank you for your prayers. Please respect our privacy. There are no further details as to the cause of his death at this time.”
Malone is one of many celebrities mourning Miller. “God f—ing dammit,” Malone posted on Twitter after Miller’s death. “You were such an incredible person. You changed so many lives. Had so much love in your heart. You inspired me throughout highschool, and I wouldn’t be where I was today without you. Never a more kind and sincere and beautiful person. I f—ing love you mac.”
He added, “We’ll make that album one day bubba. Miss you so much.”
In an August Rolling Stone article, Miller talked about his plans to collaborate with Malone. “Me and Post have been talking about doing an album,” he said.
The friends recently had a jam session with Thundercat and Frank Dukes. “It was beautiful,” Miller continued. “We were just having a great time.”