NEW YORK, NY.- Kenneth Mitchell, a Canadian actor known for his roles on the series “Star Trek: Discovery” and the film “Captain Marvel,” died on Saturday. He was 49.

He had lived with the neurological disorder amyotrophic lateral sclerosis, or ALS, which causes paralysis and death, for more than five years, according to a statement from Mitchell’s family posted to his social media.

In “Captain Marvel,” he played the father of the superhero, Carol Danvers. He was also known for portraying Eric Green on the series “Jericho,” Joshua Dodd in the series “Nancy Drew,” a hockey player in the film “Miracle,” and appeared in several other film and television series.

Mitchell played the Klingons Kol, Kol-Sha and Tenavik, as well as Aurellio, on “Star Trek: Discovery,” and voiced several characters in an episode of “Star Trek: Lower Decks.”

In a 2017 interview with StarTrek.com, he said he hoped to make viewers think differently about Klingons, the humanoid warriors whose role in the Star Trek universe has shifted over decades.

“Whether someone is good or bad is all about perspective, and it’s about understanding that culture,” he said in the interview. “You’ll get to know the Klingons on our show, and then people can decide if we really are the villains.”

Mitchell lived with his wife, actress Susan May Pratt, and their children in Los Angeles. He was born on Nov. 25, 1974, in Toronto to Diane and David Mitchell.

In 2018, Mitchell was diagnosed with ALS, according to a statement posted to his social media in August. He revealed his diagnosis in an interview with People Magazine in 2020, saying that from the moment he found out, it was “like I was watching that scene where someone is being told that they have a terminal illness.” He added, “It was just a complete disbelief, a shock.”

Mitchell said he focused on spending more time with his family and rejected a lead role in a television series that required moving back to Canada. The makers of the series “Nancy Drew” also accommodated for his illness, he told People, using a stunt double when needed. Other roles were created for him that allowed him to be seated, he added.

“This disease is absolutely horrific,” Mitchell said in the post last year, which accompanied a photo of him watching the sunset from a wheelchair on the beach. “Yet despite all the suffering, there is so much to be grateful for,” he added.

Mitchell is survived by his wife, their children Lilah and Kallum, his parents and other family members, according to the family statement.

This article originally appeared in The New York Times.