Prince’s Personal Chef Says She Tried to Warn People of Changes in Singer Before His Death (Exclusive Video)

“They just chose to ignore it,” Crystal Blanchette says in new “20/20” special investigating the drug fentanyl

Crystal Blanchette, the personal chef to Prince before his death, said she saw warning signs in the musician’s behavior and tried to warn those close to him at the time.

“There was a change in his moods. Irritable, annoyed, uncomfortable, tired. I felt like I was watching him kind of fade away,” Blanchette said in a new clip from an interview with “20/20.”

The episode, set to air on ABC Friday, will see ABC News Correspondent Bob Woodruff investigate the crisis caused by the proliferation of synthetic opioid fentanyl. Prince died in April 2016 of an accidental fentanyl overdose.

“I had saw someone that I just knew I couldn’t have in my life anymore, and I couldn’t protect him,” she said. “I did share with other people what was happening, and they just chose to ignore it.”

The episode will also feature the first interview with Prince’s half-sister, Sharon Nelson, about the singer’s death.

“He wouldn’t have taken a pill like that at all, had he known [how much fentanyl it contained],” Nelson said in a clip from the episode released earlier this week. “But when you’re in pain, you’re going to take something, hoping it relieves it… You’re not thinking like a normal person that isn’t in pain.”

In the episode, Woodruff will also investigate online fentanyl sales, go on a ride along with authorities in Lawrence, Massachusetts, who are cracking down on street sales, and go to John F. Kennedy Airport in New York City where customs agents are fighting a nonstop battle to detect incoming packages of the drug.

It will also tell the stories of Tosh Ackerman, Catherine Brady and Tiffanie Scott, all of whom took what appeared to be anti-anxiety pills or painkillers that turned out to be counterfeits made with fentanyl.

“20/20” airs on Friday, Sept. 28 at 10/9c on ABC.