Dustin Diamond died on Monday at age 44, three weeks after he was diagnosed with cancer

Fans and celebrities alike are paying tribute to Dustin Diamond, who died on Monday, three weeks after he was diagnosed with cancer. He was 44.

Diamond's former Saved by the Bell costar Mario Lopez was among the first to react to the news. "Dustin, you will be missed my man. The fragility of this life is something never to be taken for granted. Prayers for your family will continue on…," Lopez, 47, captioned a photo o the two on Instagram.

Fellow Saved by the Bell stars Tiffani Thiessen, Mark-Paul Gosselaar, Lark Voorhies and Elizabeth Berkley have also spoken out.

"I am deeply saddened by the news of my old co-star @realdustindiamond passing. Life is extremely fragile and it's something we should never take for granted. God speed Dustin," Thiessen, 47, wrote on Instagram.

In a statement to PEOPLE, Gosselaar, 46, said: "I'm deeply saddened to hear of the passing of Dustin Diamond, a true comedic genius. My sincere condolences to his family and friends. Looking back at our time working together, I will miss those raw, brilliant sparks that only he was able to produce. A pie in your face, my comrade."

Dustin Diamond
Dustin Diamond
| Credit: Noel Vasquez/Getty

Voorhies, 46, told PEOPLE "words cannot experience the grief that I am feeling right now."

"Dustin and I had a warm and special friendship, he was a caring gentleman, and my memories of him will always be cherished," she continued. "I am so very sorry he is gone. But it's exceptionally sad for his close loved ones who have do deal with his tragic death and their own great loss. My heart goes out to them at this trying time."

Berkley, 48, wrote on Instagram: "I'm grateful to have gotten to create with Dustin when we were at the beginning of our dreams coming true. I will hold onto those sweet memories and the laughs we shared. Rest In Peace."

Peter Engel, creator of the original Saved by the Bell, told PEOPLE: "I was with him for 11 years, since he was 11 years old. I had no idea he was that young when I hired him! Dustin was a comedy genius. The boy was brilliant. I've been known for not letting anyone change my words as a writer and he would come up and say let me try it this way and nine out of ten times I would end up doing it his way. When we were shooting the wedding in Las Vegas movie, I would ruin a scene by laughing so hard."

"I loved him, and he will forever be Screech to me," Engel added. "That character will live on forever."

Tori Spelling, who played girlfriend Violet Anne Bickerstaff to Dustin's Screech on Saved by the Bell, shared a lengthy statement remember their time together on Instagram.

RELATED: PEOPLE Every Day Discusses Dustin Diamond's Death

"My 1st onscreen love Dustin Diamond got his Angel wings today," the Beverly Hills, 90210 star began. "Before there was David and Donna there was Screech and Violet. Dustin was my first on-screen kiss. He welcomed me with open arms onto the set of Saved By the Bell. As one can imagine being the newbie on a hit show was overwhelming for a 14-year-old girl."

"He not only showed me around but made sure I was always ok," she continued. "Such a young gentleman. He was kind, smart, and always making everyone laugh. He was a great scene partner. He was a really good guy. I'm sad after the show we never had much contact aside from occasionally running into each other at events. I'm glad he's out of pain. He's an icon to me professionally and personally. RIP Samuel love, your Violet."

Diamond was one of the six core cast members of Saved by the Bell, which ran for four seasons from 1989 to 1993 on NBC. Unlike the others, he did not reprise his role for the Peacock reboot of the series, which debuted its first season last November.

Saved By the Bell cast
| Credit: NBCU Photo Bank

On Twitter, comedian and The Real co-host Loni Love thanked Diamond for giving "the world one of the most lovable TV characters."

"Thank you for making my childhood a little more funnier... rest now. Condolences to his family," she added.

More fans and famous friends paid tribute to Diamond. "Everyone my age grew up watching Dustin Diamond in 'Saved by the Bell.' Screech was hilarious! I'm sorry to hear about his passing today. Dustin will always be a TV icon because 'Saved by the Bell' will live on and on. Rest well," one Twitter user wrote.

"Screech appeared to be at the bottom of the Bayside hierarchy, but he gave hope to all nerds in a world of preppies and muscle-bound jocks by refusing to slink into the background," another fan wrote.

Diamond's rep confirmed the actor's cancer diagnosis to PEOPLE last month. A week later, on Jan. 21, the rep said Diamond had started chemotherapy for stage 4 small cell carcinoma, a cancer that commonly occurs in lungs, but can also manifest in the prostate or gastrointestinal tract.

In a lengthy statement announcing his death on Monday, Diamond's rep said while the cancer "spread rapidly throughout his system," Diamond "did not suffer."

"Dustin Diamond was a character in and of himself: an unpredictable spitfire who always left us shocked, but never left us bored," the statement read in part. "We are thankful he trusted us enough to share his genuine, authentic self with our team. We wish you knew him in the way that we did. We please ask that you give room for privacy to our team and Mr. Diamond's family during this tragic time, as we grieve and remember the memories spent together. This loss is as much stinging as it is sudden."