Melissa Rivers has conducted a sit-down interview with Matt Lauer for the Today show in which she reveals some chilling details about her mother Joan Rivers' death and the final moments she had with the late comedian.

In an interview that will air Monday, May 4 on Today, Melissa recalled the moments leading up to Joan's passing at the hospital.

"I just couldn't believe what I was seeing. It becomes very surreal. I had gotten emails on the plane that she was already in a medically-induced coma and they were dropping her body temperature, which I knew was bad, because that's the protocol for catastrophic brain injury," Melissa, the executive producer of Fashion Police, told Lauer in a preview clip.

Joan went into cardiac arrest at Yorkville Endoscopy Center after a routine August 2014 throat procedure on her vocal cords, which ultimately led to her September death. Melissa, 46, flew from California to New York as soon as she heard Joan was rushed to Mount Sinai Hospital. Melissa diligently remained at her mother's side.

"In my opinion, it was 100 percent preventable," Melissa said in the Today clip of her mother's death. "How about paying attention to the vital signs? How about having a properly equipped crash cart?"

However, Melissa told People she was "grateful" to have had a few days to "let go a little bit."

"I tried to make the transition as peaceful and beautiful as she would want it to be," she said.

Melissa filed a malpractice lawsuit against the clinic where Joan had her throat procedure done in January. People obtained the complaint which alleges doctors performed more procedures than consented to while Joan was sedated and they neglected to check on Joan's oxygen, blood pressure and heart rate levels.

"Not only did my mother deserve better, every patient deserves better. It is my goal to make sure that this kind of horrific medical treatment never happens to anyone again," Melissa reportedly said in a statement at the time.

Melissa and Joan both starred in the reality series Joan & Melissa: Joan Knows Best together. They also competed on the second season of The Celebrity Apprentice.