“He loved the Steelers and was just out with friends watching the game last night,” a music industry source tells PEOPLE.
The rapper’s beloved team was not playing during Thursday night’s 2018 regular-season opener, instead, the Philadelphia Eagles faced off against the Atlanta Falcons.
His casual night with friends seemed so benign, “that’s why this is such a shock,” the source added.
“Everyone who he worked with was aware that he was delicate, but thought it was because of the new album, nerves, nothing like this.”
Miller just dropped his fifth and final studio album Swimming on Aug. 3.
“At his record release in New York he was happy taking pictures, we felt like he was back. He wasn’t even drinking in New York,” the source tells PEOPLE.
“He was an artist’s artist; everyone loved him,” the industry insider added.
Miller, whose real name was Malcolm McCormick, died Friday of a suspected drug overdose, PEOPLE confirmed. He was 26.
The younger rapper was pronounced dead at 11:51 a.m. at his Studio City, California home, the Los Angeles County Department of Medical Examiner-Coroner confirmed to PEOPLE.
While his cause of death has not yet been revealed, a different source tells PEOPLE Miller went into cardiac arrest.
Throughout his life, Miller was very open about his struggles with sobriety. Following his Macadelic tour in 2012 and the release of his first studio album Blue Slide Park, Miller admitted he turned to drugs to cope with stress.
“I love lean; it’s great… I was not happy and I was on lean very heavy,” Miller told Complex in 2013. “I was so f—ed up all the time it was bad. My friends couldn’t even look at me the same. I was lost.”
Miller also battled depression. “I had a drug problem for a long time. It wasn’t just in music, but I definitely was going through a drug problem and I think it was more my state of mind. I was just pretty depressed,” Miller said to Larry King in 2015.
One year later, Miller admitted during a documentary for FADER that “he hates being sober” but he’d “rather be the corny white rapper than the drugged out mess who can’t even get out of his house. Overdosing is just not cool.”
However, last month he told Rolling Stone he doesn’t classify himself as a drug addict. “If a bunch of people think I am a huge drug addict, OK. Cool. What can I really do? Go talk to all those people and be like ‘Naw man, it’s really not that simple?'”
“Have I done drugs? Yeah. But am I a drug addict? No.”
If you or someone you know is in need of help, please contact the SAMHSA substance abuse helpline at 1-800-662-HELP.