As his side project, Adrenaline Mob, was on tour in New York, the band's website released a statement saying that the iconic Twisted Sister drummer, A.J. Pero, was found unresponsive in the band's tour bus, apparently having passed away from a heart attack.

At only 55, the Twisted Sister drummer had achieved legend status, having worked on the heavy metal band as well as with some of the biggest names in the genre, including Ozzy Osbourne and Eric Carr - now, he's passed away at 55, leaving his legacy behind.

According to Yahoo! Music, Twisted Sister's drummer didn't die on the tour bus, but rather on a hospital in Poughkeepsie, New York, after he was found unresponsive; in the hospital, he later suffered what was apparently a heart attack, and unfortunately passed away then.

The full name of the Twisted Sisters drummer was Anthony Jude Pero, though he preferred to go with A.J. He had been a part of the iconic band since 1982, the project for which he is most famous, even though he left in 1986, only to return in 1997 - his drumming abilities were featured, however, in every single one of their albums except for "Love is For Suckers," and has been called one of the central parts of the band's decades-long success.

"Today, I lost a brother," said Dee Snider, the lead vocalist of the iconic band, in a statement to Rolling Stone Magazine about the passing of the Twisted Sister drummer. " His sledgehammer assault on the drums helped drive Twisted Sister and me to greatness and inspired me to rock every single show. My heart breaks knowing I will never feel the power of his beat behind me, or turn to see his face smiling broadly from the sheer joy he got from doing what he loved. I will always remember that smile. R.I.P., my friend."

The heartfelt tribute was only one in the many directed at the famous Twisted Sister drummer, including one from the band's Facebook page, thanking fans for their support and prayers.