Actor Kenneth Mitchell died Saturday at the age of 49 from ALS complications. The news of his passing was revealed in an Instagram post on his account.

For five and a half years, Ken faced a series of awful challenges from ALS, the post said . And in truest Ken fashion, he managed to rise above each one with grace and commitment to living a full and joyous life in each moment. He lived by the principles that each day is a gift and that we never walk alone. His life is a shining example of how full one can be when you live with love, compassion, humor, inclusion and community. Ken was an inspirational work of art to all the hearts he touched.

Mitchell was best known for his work on Star Trek: Discovery, where he played Kol, Kol-Sha, Tenavik and Aurellio. He also played Carol Danvers father in Captain Marvel and Joshua Dodd in Nancy Drew.

Mitchells wife, Susan May Pratt, addressed his passing in an Instagram post on Sunday , writing in the caption, My dear husband Ken has left us.

Mitchell was diagnosed with amyotrophic lateral sclerosis, or ALS, in 2018. The neurological disease required him to start using a wheelchair in 2019.