Entertainment TV Jurnee Smollett Remembers Late Costar Michael K. Williams on His Birthday: 'Miss You' Michael K. Williams died in September after an accidental overdose By Dory Jackson Dory Jackson Dory Jackson is an Associate Editor for PEOPLE's digital TV team. While at the brand, she's had the opportunity to interview a long list of celebrities, from Kate Hudson to Pierce Brosnan to Billy Porter. She has also helped recap popular TV shows like 'The Real Housewives of Beverly Hills,' 'Sister Wives' and 'Vanderpump Rules.' The New York-based Maryland native graduated from Randolph-Macon College in May 2016 with a focus on Communication Studies and Journalism. She came to PEOPLE in March 2021 after working at a number of major news companies, including Newsweek and Us Weekly. People Editorial Guidelines Published on November 22, 2021 04:11PM EST Jurnee Smollett paid tribute to her late Lovecraft Country costar, Michael K. Williams, on what would have been his 55th birthday. On Instagram Monday, Smollett, 35, shared a carousel of photos from her time with Williams on the HBO show's set. The pair's former castmate Jamie Chung also re-shared Smollett's post on her Instagram Story. "Happy birthday, my brother," Smollett captioned the post. "I miss you so." Williams died on Sept. 6 at age 54 after he was found dead in his Brooklyn penthouse apartment. JURNEE SMOLLETT/ INSTAGRAM "It is with deep sorrow that the family announces the passing of Emmy nominated actor Michael Kenneth Williams," Williams' rep told PEOPLE at the time. "They ask for your privacy while grieving this unsurmountable loss." The New York City Office of the Chief Medical Examiner later announced that Williams died by "acute intoxication by the combined effects of fentanyl, p-fluorofentanyl, heroin and cocaine." The manner of death was ruled an accident. Michael K. Williams Career in Photos After Williams' passing, Smollet said she was "struggling" to accept the news that her friend was gone. I called him. I called him over & over until my brain said stop, he's gone. I couldn't breathe. Taken awhile for my brain to metabolize how the world can continue to spin w/out him here in the physical form," she wrote on Instagram. "I take comfort in knowing that you're finally free, somewhere dancing, being mighty, showing the angels how to really get it. Btw — You still owe me that dance … & our Bulls Jerseys. I love you." Michael K. Williams. Amy Sussman/FilmMagic Smollett also subtlety honored Williams at the 2021 Emmys by wearing a hair accessory with his initials on it. Williams' storied career included roles in When They See Us, F Is for Family and Motherless Brooklyn. His role on Lovecraft Country earned him his fifth Emmy nomination in July. Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories. Williams — who had been vocal about his addiction and mental health struggles — once said he's "very fortunate" for the success he's had in his career. "There's no words to say how fortunate I am, you know?" he previously told The Hollywood Reporter. "To keep it real: To be a Black man in Hollywood — not only just to land those two roles, but as a Black man in Hollywood, to go on those two shows back to back, you know, on such a great network as HBO — man, to say I'm fortunate is an understatement." If you or someone you know is struggling with addiction, please contact the SAMHSA substance abuse helpline at 1-800-662-HELP.