What's Happening!! child star Danielle Spencer passed away on Monday, August 11, 2025, as confirmed by her former co-star, Haywood Nelson. They worked together in the dark comedy sitcom from 1976 to 1979.Nelson paid tribute to her co-star and her character in What's Happening!! in an Instagram post on Tuesday, while announcing her death at 60 years old.Alongside a collage of the actress' photos, including one from her time in the sitcom, he wrote:"Dr. Dee, our brilliant, loving, positive, pragmatic warrior, without fail, has finally found her release from the clutches of this world and a body. We celebrate Danielle Spencer and her contributions as we regret to inform her departure and transition from a long battle with cancer." View this post on Instagram Instagram PostAnother Instagram post by her brother, Jeremy Pelt, confirmed her cause of death. He wrote that her sister "lost her battle with cancer." Their family friend and spokesperson, Sandra Jones, also told ABC News that she died from gastric cancer and cardiac arrest.The late actress was diagnosed with breast cancer in 2014 and had to undergo a double mastectomy. However, that wasn't the only health struggle she endured throughout the years. According to CBS News, she was in a major car crash in 1977.The accident killed her stepfather and left her in a coma for three weeks, along with spinal and neurological problems that would need multiple surgeries years later.In 2004, she was diagnosed with spinal stenosis and was briefly paralyzed. 14 years later, in 2018, Danielle Spencer had to get an emergency surgery for a bleeding hematoma, which, according to CBS, is still related to the 1977 crash.Danielle Spencer played the sister, Dee Thomas, in What's Happening!!Danielle Spencer as Dee in What's Happening!! (Image via @DrDanielleSpencer/Facebook)Danielle Spencer is best known for starring in the 1970s ABC sitcom What's Happening!! alongside Ernest Thomas, Haywood Nelson, Fred Berry, Mabel King, and more. It was her first and most significant acting project to date.In the sitcom about three teenage boys growing up in a neighborhood in South Los Angeles, Spencer played the boys' younger sister, Dee Thomas.Dee's character is famous for being serious, smart, and for her endless stream of deadpan roasts of his brothers, especially of Raj (Ernest Thomas) and his friends Rerun (Fred Berry) and Dwayne (Haywood Nelson).She appeared in all 65 episodes of the three-season run of the sitcom, with "Ooh, I'm gonna tell mama" becoming her famed catchphrase.After the third season of What's Happening!! ended in 1979, Spencer left acting to study veterinary medicine. She attended UC Davis and Tuskegee University, becoming a veterinarian in 1996.In the mid-1980s, she reunited with the original cast for the spinoff What's Happening Now!, which ran for three seasons. Spencer appeared in 16 of its 66 episodes as a recurring character.Danielle Spencer played a veterinarian in As Good as It Gets, and her last acting role was in 2001, a guest-starring role in Days of Our Lives.