Kurt Busch, himself a NASCAR Cup Series champion, has opened up about the sudden death of his younger brother, Kyle Busch, detailing the rapid progression of his illness and his final moments in the hospital.

Kyle Busch, a two-time NASCAR Cup Series champion, died on May 21 after falling ill while using a racing simulator. He had contracted pneumonia, which quickly developed into sepsis, leading to his death at the age of 41.

During an interview on the "Today" show, Kurt Busch described the rapid escalation of his brother's condition. He recounted that their crew chief, Andy Street, first heard Kyle coughing in a restroom after a simulator session. Street then found Kyle against the wall with blood in the sink. An ambulance was called, and while Kyle was initially expected to miss the Coca-Cola 600 race at Charlotte that weekend, he passed away just hours later.

Kurt Busch was present at the hospital throughout the day, holding onto hope for his brother's recovery. "It's just everything had plateaued so fast," he said. "It just escalated so fast." He noted that his father, Tom Busch, made the difficult decision not to see his son in his final hours, preferring to remember him otherwise.

Recalling his last words to his brother, Kurt Busch became visibly emotional. "I said, 'I got you man. Come on. I got you. I got you, come on. Be strong,'" he shared. "Just wasn't fair."

His wife, Samantha Busch, along with their son Brexton and daughter Lennix, were present at Charlotte Motor Speedway for the Coca-Cola 600 just three days after Kyle's passing. The NASCAR community showed their support for the family during this period.

Samantha Busch recently announced that the iconic M&M's car Kyle Busch drove for Joe Gibbs Racing will return for a single race. Driven by Ty Gibbs in the No. 54 car at Bristol, Kyle's favorite track, the tribute aims to honor his memory. "Seeing Mars and Joe Gibbs Racing come together to honor Kyle this way is incredibly emotional for me," she stated in a video montage of his career highlights. "The M&M's car holds so many memories from our life together, and seeing it back on the track knowing Kyle won't be the one behind the wheel is going to be both heartbreaking and beautiful all at once."

She added that the return of the iconic colors to the No. 54 car feels like bringing a piece of Kyle back to a track he loved. "Kyle loved Bristol and Bristol loved Kyle. Being back with our NASCAR family under the lights to celebrate his life, his career and the memories he gave all of us is something we will never forget."