Ryan Knight Dies: The Real World and The Challenge Alum Mourned by Co-Stars--See Their Touching Tributes

Several former cast members of The Real World: New Orleans and The Challenge took to social media during Thanksgiving to mourn the death of Ryan Knight,  their co-star and friend.

He was found dead at a residence in Kenosha, Wisconsin on Thanksgiving Day. Knight was 28, police said.

Officers responded to a 911 call and discovered him unconscious and not breathing. Paramedics were unable to revive him. Knight's death is being investigated.

He had on Tuesday exchanged tweets with Sahar Dika, who starred with him on The Real World: New Orleans in 2010.

"Four years ago, we created a family in New Orleans that is unbreakable. Today, we lost you," she said on her Instagram page on Thursday, alongside a pic of the two.

"Knight, there were so many times we argued and screamed... But it always ended in a hug and a kiss and telling each other how much we loved each other," she said. "You are my family and I shared an experience with you and 7 others that will never be forgotten, not even parted with death."

"I love you and I cherish the memories we spent together..." she said. "I was supposed to see you this weekend and in a flash, you are gone. Never forgotten! I love you so much this doesn't even feel real... Rest in peace to my friend, my brother Ryan Knight. You have my heart, always."

Dika also posted more photos of the two with friends.

Here are more touching tributes to Knight posted by other former co-stars:

Jemmye Carroll, his on-again, off-again girlfriend and star of The Real World: New Orleans:

"Words will never be enough to justify the connection we shared and the pain I will forever feel. RIP @Knight_MTV," she tweeted.

She also posted a cell phone screenshot of a list of voicemails he had left her, joking that he knew she hated them, and photos of the two together.

Ryan Leslie, The Real World: New Orleans:

Ashlee Feldman, The Real World: New Orleans:

"And in an instant your entire day can change," she wrote on Instagram. "I slept in a room with Ryan Knight for 3 months and we laughed, yelled, cried, screamed and then laughed again. He had the personality that could charm a rattlesnake. He had the personality that makes him unforgettable. Today we lost a good one. I love you roomy."

Zach Nichols, The Challenge (and The Real World: San Diego):

"You lived your life in the fast lane, and your smile was contagious. My bunkmate, my buddy. Rest easy pal, I'll miss you. @Knight_MTV," he tweeted.

"He also posted on Instagram, alongside a photo, "Controversial, outspoken, and hilarious. You lived your life with a reckless abandon, and everyone loved you for it. Anyone who knew you would say you were rough around the edges, but on the inside you truly cared about people and their happiness."

Frank Sweeney, The Challenge:

Camila Nakagawa starred on The Challenge with Knight and Diem Brown, another former cast member who recently died at age 32 after battling cancer.

After learning about Knight's death, Nakagawa posted a heartbreaking tweet and a photo of her two friends.

"I love you guys," she said. "Knight, tell Diem Hi for me. #RIPKnight #RIPDiemBrown."

(Pictured above: The Challenge: Rivals II cast members, including Knight, top and center, second to his right, appear at the season's reunion party in New York on Sept. 25, 2013.)

On Monday, Knight posted an inspirational tweet about living, which has been shared hundreds of times since his death.