The stunning news of Eagles co-founder Glenn Frey's death has left the band's longtime manager, Irving Azoff, struggling to make sense of his loss.

"I can't believe he's gone," Azoff told Billboard after hearing of Frey's passing yesterday. "I can’t believe everything we accomplished. It was a staggering body of work and just an amazing run. I don’t think there will ever be another American band [that's] as successful."

Azoff's rise to power in the entertainment industry was fueled largely by his success with an early roster of management clients that included the Eagles and Dan Fogelberg. After the Eagles split in 1980, Azoff worked as chairman of MCA Records for much of the decade before moving on to found his own imprint, Giant Records, and he reunited with the Eagles by helping broker the deal that brought them back together for their wildly popular Hell Freezes Over. Following a move back into management, he helped broker a series of very lucrative touring deals for the band.

"I wouldn’t have been the success that I’ve been without Glenn Frey teaching me, leading me and supporting me for over 40 years," said Azoff. "He was a passionate family man, a great father, a great humanitarian, and he’s gone way too soon."

Frey's death was attributed to "complications from rheumatoid arthritis, acute ulcerative colitis and pneumonia," but Azoff told The Wrap that some of his health problems were attributed to a medication — which he refused to name under advice from an attorney — that he'd been taking for his arthritis.

"The colitis and pneumonia were side effects from all the meds," said Azoff. "He died from complications of ulcer and colitis after being treated with drugs for his rheumatoid arthritis which he had for over 15 years."

Now, says Azoff, he and the surviving band members are left to say goodbye to the band after a 20-year reunion run that "nobody regrets" while wondering what they might have been able to add to their legacy with a little more time. Saying their next project would have been called "Pigs Are Gonna Fly," Azoff admitted the obvious: "It doesn't look like" the group will be able to continue.

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