Over the course of its 25-year history, The Challenge has introduced viewers to hundreds of memorable and lovable contestants, some of whom have been honored by the series after their tragic passings. The show premiered in 1998 (then called Road Rules: All Stars), and eventually evolved into Real World/Road Rules Challenge. It finally took on an all-encompassing title, The Challenge. The reality competition show aimed to take stars from two already popular MTV shows (Road Rules and The Real World), and pit them against each other in physical competitions. Fans of the original programs could tune in, and root for their favorite stars in a new setting.

The Challenge's format is unique from other reality TV series because its contestants typically return to compete multiple times. This distinct factor has allowed the stars (and fans of the series) to form long-lasting relationships with those who appear on The Challenge. Following the tragic passings of reality stars from the series, other competitors (and the show's viewers) have kept their memory alive. It's important to look back at the legacies of those who have passed away, and celebrate their lives on and off of The Challenge.

4 The Challenge's Diem Brown

Diem appeared on various The Challenge seasons, where she impressed her fellow cast mates with her enduring kindness and determination. Not long after Diem's first appearance on the show, during The Challenge: Fresh Meat, she was diagnosed with ovarian cancer. She chose to continue competing despite her condition. After undergoing treatment, Diem went into remission, and following her initial battle against cancer, she advocated for other patients. Fans were very saddened by her passing, and when @thechallenge tweeted, "RIP to two people that always made us smile. Gone but never forgotten - Ryan Knight and Diem Brown," fans reacted with heart emojis. One, @yaardiegirl, said: "Deem was such a joy."

Diem's experiences during her treatment and hospital visits inspired the organization MedGift, which acts as an online registry for those receiving treatment for medical conditions. In 2014, Diem's cancer returned. Despite her diagnosis, she agreed to compete on The Challenge: Battle of the Exes 2, alongside her ex, Chris "CT" Tamburello, who was a close friend.

After filming a few episodes, her condition worsened, until she was medically disqualified from the competition. She was flown back to New York to undergo emergency hospitalization. Tragically, Diem passed away in November 2014, at the age of 32. Her final The Challenge season was dedicated to her memory, along with the memory of fellow cast mate, Ryan Knight.

3 The Challenge's Ryan Knight

Ryan Knight on The Challenge. He is facing the camera, sitting against a blurred background of a desert environment.

Ryan passed away in 2015, shortly after Diem did, and The Challenge: Battle of the Exes 2 featured both of their last appearances in the series. He was known for his sense of humor and easygoing personality, even though the game environment was stressful. At the age of 29, Ryan tragically died, following an accidental overdose in Kenosha, Washington. Outside of competing on The Challenge, Ryan had enjoyed hockey, and joking around with friends and family.

Ryan's memory is kept alive by his fellow The Challenge competitors, many of whom have spoken out about the impact he had on them. Jemmye Carroll, Ryan's ex-girlfriend and partner on Battle of the Exes 2, has commemorated their time together through social media, often posting pictures and reminiscing. One of Ryan's close friends, Zach Nichols, talked about the impact Ryan had on him during a later season of The Challenge, in an emotional moment a year after his passing. In his final remarks on the show, Ryan described himself as, "The man, the myth, the legend. Often imitated, never duplicated."

2 The Challenge's Michelle Parma

Michelle Parma from The Challenge. She is looking away from the camera, standing against a background of what appears to be a store. She is wearing a black shirt and standing beside someone else who is just out of frame.

Michelle competed on one of the very first The Challenge seasons back in 2001. Known for her free spirit and willingness to try anything, Michelle participated in a wide variety of different experiences across Europe during her initial Road Rules season. She showed just how determined she was to live life to the fullest. Although the cast of Michelle's Road Rules season could get chaotic at times, she was consistently determined to maintain a positive and calm attitude, which made the season more pleasant overall.

In 2002, Michelle was tragically killed in a car accident while traveling from Dallas to Texas. Another driver lost control, and crossed the median. The crash also killed Michelle's cousin, Mandie Parma, and left other drivers severely injured. Michelle was only 27 years old at the time of her passing. Although her death was over 20 years ago, Michelle is still remembered by those in The Challenge community, after her impressive performance on Extreme Challenge. Most of all, her genuine personality left a lasting impression on Road Rules viewers. Her impactful seasons of Road Rules and The Challenge serve as a reminder of her inspiring outlook on life.

1 The Challenge's Danny Dias

Danny Dias from The Challenge. He is facing the camera, smiling widely, and standing against a tree with a backdrop of hills and greenery behind him.

Danny appeared on The Challenge: Gauntlet 2, and was eager to compete against his fellow players. Before appearing on The Challenge, Danny was featured on The Real World. Outside of reality TV, he worked with an organization dedicated to AIDS research. In 2017, Danny sadly passed away due to long-term substance abuse complications at the age of 34. His enthusiasm for competing on The Challenge, and dedication to causes he cared for in his personal life, are his enduring legacy. While his time on The Challenge was short, he will always remain an integral part of the series.

It's very sad that these The Challenge alums have passed away, but remembering them is important and worthwhile. They all added to the show they appeared on, thanks to their unique personalities and interesting gameplay. Their spirits live on, and the energy that they brought to the series made them very special. While their passings were tragic, their bravery and charisma will never be forgotten. Their friends, families and loved one will remember them forever, and so will the series' loyal fans. The alums left the world too soon, but made it a beautiful place.

Sources:@yaardiegirl/Twitter, @thechallenge/Twitter