(CNN) -- Tributes to "Green Mile" actor Michael Clarke Duncan poured in Monday on Twitter as word of his death spread.
Here's how some celebrities and people who knew Duncan remembered him:
Adam Baldwin, actor
"R.I.P. dear Michael. We were all honored & priviliged to know you & work with you on 'Chuck.' Farewell, gentle giant."
Zachary Levi, actor
"Blessed to have had the opportunity to work with Michael Clarke Duncan while he was still with us. He was a kind soul that will be missed."
Roger Ebert, film critic
"Michael Clarke Duncan passes at 54. A striking screen presence."
MC Hammer, rapper
"One of the best among Men on earth. A gentle Giant. Loved him. Pure class and grace. RIP my friend."
Terry Crews, actor
"Rest in Peace to my brother who paved the way for me and many Black actors, Michael Clarke Duncan."
Steve Harvey, actor and radio host
"I will miss my friend, Michael Clarke Duncan. What an incredible soldier in God's Plan."
Olivia Munn, actress
"Michael Clarke Duncan always had a smile on his face & a big bear hug ready for you. My thoughts & prayers are with his family&friends. RIP."
Jordin Sparks, singer and actress
"RIP Michael Clarke Duncan. Thank you for being so kind to me & for sharing your talent with the world. You will be truly missed."
Mario Lopez, TV host and actor
R.I.P Michael Clarke Duncan... One of the nicest & most professional guys I've had the pleasure of knowing. So sad."
David Boreanaz, actor
R.I.P. my friend MCD. I will miss you.