Actor Michael K. Williams — who most notably played the character Omar Little on hit TV series “The Wire” — was found dead on Monday in his Brooklyn penthouse, due to what is suspected to be a heroin overdose, according to multiple reports.

Williams, 54, was vocal about his issues with drugs over the course of his career. He even admitted during the filming of “The Wire” that when he was getting into the role of Little, a character who robbed drug dealers, it affected him in his real life.

Klay Thompson, who spent time with Williams during the filming of a commercial, posted a tribute to the late actor to his Instagram account on Tuesday.

It was such an incredible experience working with Mike . We talked about our Bahamian roots and our love for the Caribbean . I was such a fan of his work and involvement with the youth of NYC. A true leader , you will be so missed brother @bkbmg

Thompson had established a bond with the Williams, presumably during the shooting of his Kaiser Permanente commercial which first aired in 2019. The commercial, which is a play-on of the chess scene in Ingmar Bergman's "Seventh Seal", a 1958 Swedish film in which a classic scene features the protagonist challenging Death, yes, Death, to a chess match.

In the commercial, Thompson plays the protagonist, while Williams plays the role of Failure. The black and white ad spot closes with Klay proclaiming, “I still know how to beat you”, followed by the Golden State star pulling up for a jumper as waves from the ocean crash in the background.

Like Thompson, Williams was an outspoken proponent for social justice issues. In 2015 Wiliams became an ambassador for ending mass incarceration for the American Civil Liberties Union. He spoke on some of the things he hoped to accomplish in an interview with The Guardian.

“I could have been Eric Garner,” he said. “I could have been Michael Brown or Trayvon Martin. My goal is to end mass incarceration and to have more dialogue about how can we stop the government filling up jails with low-level, non-violent drug offenders and people with mental illnesses or addictions. Those are health issues, not criminal ones.”