Brendon “Alias” Whitney, the rapper/producer who co-founded the record label Anticon, died Friday at the age of 41. A tweet by Whitney’s friend and collaborator Sage Francis revealed that he died of a heart attack.

Anticon confirmed the news yesterday with a tweet that reads, “Just received news of a major loss – the passing of our dear friend and Anticon co-founder @AliasAnticon,” the Los Angeles-based hip-hop label tweeted. “We will always remember him for his incredible heart and talent, and the support he gave us all. Rest in peace Brendon Whitney.”

Just received news of a major loss – the passing of our dear friend and Anticon co-founder @AliasAnticon. We will always remember him for his incredible heart and talent, and the support he gave us all. Rest in peace Brendon Whitney. pic.twitter.com/vJ3pULqwgJ

— anticon records (@anticon) March 31, 2018

Whitney started Anticon in 1998 in collaboration with likeminded hip-hop artists like Jel, Pedestrian, Doseone, Odd Nosdam, Why?’s Yoni Wolf and Sole. He released 15 albums and EPs under the moniker Alias from 1999 to 2014 before shifting his focus to production. Last year Whitney helped produce Doseone & Mestizo’s A7PHA album. 2014’s Pitch Black Prism is his most recent album, which you can hear and buy here.