Billie Joe Armstrong's Rehab is 'Killing Everyone,' Green Day Bassist Says

Mike Dirnt tells Kerrang! magazine his friend is battling demons in a rehab stint.

Little is known about what sent Green Day singer Billie Joe Armstrong to a rehab facility following an onstage rant at the iHeartRadio Music Festival last month, but to hear GD bassist Mike Dirnt tell it, the situation is pretty serious.

"Billie doesn't take things lightly and he wouldn't take rehab lightly, either," Dirnt said in a new interview in Kerrang! magazine. "He's in the middle of some really big things, but we're going to pull through. It's killing everyone. Green Day has never been a band that sits still, but sometimes you have to step back and let life go on rather than try to control everything."

In an earlier interview, Dirnt said the hectic schedule to record and promote the band's album trilogy may have contributed to Armstrong's issues. Regardless of the causes, Dirnt said his #1 focus right now is making sure his longtime friend and bandmate gets well.

"I know that my friend's life is in danger and that's all I care about," he said. "We're brothers-in-arms waiting for Billie to return healthy, but we're not going to force anything."

Earlier this week, the band's longtime producer and Warner Bros. Records chairman Rob Cavallo described Armstrong's rehab stint as "no joke" and said it could put off more previously scheduled tour dates.

"His doctors are still evaluating," Cavallo said. "All I can say is I don't know if we'll see him before or after Christmas. It's basically undetermined when he'll be back."

In late September, Green Day announced that singer Billie Joe Armstrong was seeking help with unspecified substance issues.

"Billie Joe is seeking treatment for substance abuse," read a statement on their Facebook page. "We would like everyone to know that our set was not cut short by Clear Channel and to apologize to those we offended at the iHeartRadio Festival in Las Vegas. We regretfully must postpone some of our upcoming promotional appearances."

Armstrong launched into a rant during Green Day's September 21 performance at iHeartRadio after being told that the band needed to wrap up their set, shouting "I'm not f---ing Justin Bieber, you motherf-----s. You've got to be f---ing joking ... I got one minute left." Green Day then smashed their instruments before departing the stage. And earlier this month, Green Day were also forced to cancel a concert in Italy after Armstrong was hospitalized. His bandmates would subsequently tell MTV News that he had "severe dehydration,"
 though he recovered in time to perform at the 2012 MTV Video Music Awards.

Following Armstrong's hospitalization, the band canceled a series of promotional performances, and on Monday, they announced that they would have to pull out of a headline slot at the October 27 Voodoo Music + Arts Experience festival in New Orleans.

"Canceling shows is something we rarely do," said drummer Tré Cool, in a statement announcing the canceled Voodoo gig. "We never want to let our fans down, and we are grateful for all of you being understanding during this time."

Green Day still plan to release the next album in the series, ¡Dos! on November 13.