Twisted Sister and Adrenaline Mob drummer AJ Pero was found unresponsive on Adrenaline Mob’s bus this past Friday, March 20, 2015. It is reportedly due to a heart attack, his longtime agent said he had been complaining of a sore arm and took a few days off to rest. This incident took place in Poughkeepsie, NY, where they were supposed to perform later that evening.

Twisted Sister guitarist Jay Jay French joined Adrenaline Mob on stage at a tribute show at the Starland Ballroom in Sayreville, NJ this past Saturday, March 21, 2015 doing “You Can’t Stop Rock N Roll.” View footage below.

Adrenaline Mob issued a statement on their Facebook page in regards to this:

My friend, my brother, my band mate passed away today. My heart is broken. RIP A.J. Pero.

— Dee Snider (@deesnider) March 20, 2015

I have to say, the passing of AJ PERO just doesn’t seem real. It will be at his wake in NY on Wednesday. #EndOfAnEra

— Dee Snider (@deesnider) March 22, 2015