Actor Karl Shiels passed away Monday, although the cause of death isn’t clear.

The actor’s agent Lisa Cook confirmed his death Tuesday, according to a report published by Page Six. He was 47 years old.

Karl Shiels: remembering a singular figure on stage and screen https://t.co/xpRZNQTXVp via @IrishTimesCultr

— Irish Times Culture (@IrishTimesCultr) July 16, 2019

Shiels reportedly passed away in his sleep after repeatedly falling asleep on set of soap opera “Fair City,” The Sun reported. (RELATED: Fashion Icon And Socialite Gloria Vanderbilt Dies At 95)

“Karl was a uniquely talented individual, simultaneously intense, lighthearted, funny, sharp-witted, outspoken and intensely powerful as an actor, director and artistic director of the Theatre Upstairs – where he was such a support and mentor for young writers, actors and directors – and of his own company Semper Fi before that,” Cook said in a statement regarding the actor’s death. “Karl was a remarkable force in Irish theatre and hugely loved and respected by all who worked with him.”

I’m so moved by all the tributes to #KarlShiels. I feckin’ hope he knew how loved & well regarded he was from independent artists needing a break to the big houses. Theatre can be a draining & lonely industry. I hope we tell each other the good stuff while there’s still time.

— NiamhNic (@NiamhNic) July 16, 2019

“…Karl was also our friend, the loving father to his two girls, a man loved by so many who knew him and worked with him and he will be deeply mourned by all who did,” her statement continued. “Our hearts are broken but today our thoughts are with his partner Laura and his family, his children and their mother Dearbhla and his many close friends among whom we count ourselves lucky to have been for so many years. And for the rest of us, as Karl himself would so often say……’Onwards…'”