The rapper was 26.
Authorities say Miller's body was discovered at around noon at his San Fernando Valley home. The Pittsburgh native—birth name Malcolm James McCormick—was reportedly pronounced dead at the scene.
The tragic news arrives about a month after Miller released his fifth studio album, Swimming , in which he addressed his battle with substance abuse and self-love. He was expected to kick off the album's supporting tour next month.
Miller was charged with a DUI back in May after he crashed his vehicle into a power pole in Southern California. He spoke about his arrest in a sit-down interview with Zane Lowe earlier this summer.
"I made a stupid mistake. I’m a human being," he said on Beats 1. "But it was the best thing that could have happened. Best thing that could have happened. I needed that. I needed to run into that light pole and literally have the whole thing stop."
Miller began rapping at the age of 14, and went on to release his first mixtape, But My Mackin’ Ain’t Easy , a year later. In 2010, Miller inked a deal with Rostrum Records and dropped his breakout project K.I.D.S. He released his debut album, Blue Slide Park , in the following year. Miller would go on to release four more albums, including the aforementioned
Swimming, and also produced music under his Larry Fisherman alias.

Source: https://www.complex.com/music/2018/09/mac-miller-dead-at-26