Former MEGADETH drummer Nick Menza passed away Saturday night (May 21) while performing with the band OHM: at The Baked Potato in Studio City, California. He was 51 years old.

Nick collapsed during the third song of OHM:'s set. Earliest reports indicate he suffered a massive heart attack and was pronounced dead upon arrival at hospital. No other details are being released at this time.

One person who was present at The Baked Potato last night told BLABBERMOUTH.NET: "It appeared to be a seizure but [Nick] stopped breathing. Two patrons took over and began CPR until EMS arrived. EMS worked on him for 25-plus minutes, including adrenaline shots, three shocks and non-stop compressions."

OHM:'s manager Steve Bauer told CNN: "The group's bassist texted me last night after it happened. We are all still in shock."

Nick's biographer and friend J. Marshall Craig said: "We ask for prayers for Nick's family, his family, and especially his two sons and their mother, Teri.

"He just spent nearly two weeks with the boys in the Pacific Northwest and was absolutely glowing. He was scheduled to fly to my home in Cape Cod tomorrow so that we could finish the comic-book version of the book we wrote on his life, 'MenzaLife', both of which were slated for release late next month. This morning we are all too numb to think about anything but Nick's family.”

Nick's manager Robert Bolger said: "Along with your prayers and wonderful thoughts and memories of this incredible man and musician, we ask that fans respect his family’s need for privacy at this absolutely tragic time."

Menza's friend Allen Hall wrote on Facebook: "We lost an amazing talent and fantastic person yesterday. Nick Menza was the nicest and most sincere guy you should ever hope to meet.

"He would take the shirt off his back to help you if you needed it. He had a passion for artwork, not just metal music.

"Nick, you were taken too soon, it must have been a mistake, the world was a better place with you in it. I will miss you dearly my friend."

MEGADETH mainman Dave Mustaine tweeted: "Tell me this isn't true. I woke at 4am to hear Nick Menza passed away on May 21 playing his drums with Ohm at the Baked Potato. #nickmenzarip."

Mustaine's son, Justis, also paid tribute to Nick on Twitter, saying: "Rest in peace Nick Menza."

A Facebook post from The Baked Potato stated simply: "RIP Nick Menza."

MEGADETH bassist David Ellefson wrote on Facebook: "Condolences to the Nick Menza family and friends. We have lost a gentle giant... A true artist and friend to us all."

Former MEGADETH guitarist Marty Friedman said in a Facebook post: "We all know the great and unique drummer that Nick Menza was, but he was also a trustworthy friend, a hilarious bandmate, as well as a very loving dad. I'm beyond sad. [I] did not see this coming at all. RIP brother."

Ex-MEGADETH guitarist Glen Drover said: "I'm super shocked after reading the news about Nick last night. As some of you know, it was me, Nick, Dave [Mustaine], and Jimmy Macdonough in 2004, who became the first lineup of MEGADETH after the original breakup in 2001. Although it was short lived (with my brother Shawn taking over for Nick), it was nice playing and getting to know him a little for that very brief period. He seemed like a good guy. Very quiet, and what I remember most is that when he played drums, he used ride cymbals for his crashes. For those who don’t know, it's very, very loud!!!!! But it's okay; I still have some of my hearing intact. Ha."

Menza joined MEGADETH for the 1989 recording "Rust In Peace" and for the next nine years became associated with the band's "classic" and most profitable era.

He claimed in a 2015 interview that the attempted reunion of the "Rust In Peace" lineup failed to materialize because Dave Mustaine "didn't wanna show me any love at all."

The drummer said that he was approached by Mustaine and bassist David Ellefson to replace Shawn Drover at the end of 2014, and that he had started working out new tracks with the band. But the plan collapsed after he was offered a contract he described as "very unfair."

In addition to Menza, OHM: featured another ex-MEGADETH member, guitarist Chris Poland.

Menza joined OHM: last year after the passing of the band's previous drummer, David Eagle, who suffered a heart attack and had open-heart surgery in May 2015.

Last week, it was announced that Nick would unveil an art collection crafted from the new medium of "rhythm-on-canvas" on June 16.

Menza had been working with art team and publisher SceneFour on the collection titled "Rhythm Hits The Wall".

TELL ME THIS ISN'T TRUE! I woke at 4 AM to hear Nick Menza passed away on 5/21 playing his drums w/Ohm at the Baked Potato. #nickmenzarip — Dave Mustaine (@DaveMustaine) May 22, 2016



Condolences to the Nick Menza family and friends. We have lost a gentle giant... A true artist and friend to us all. #ripnickmenza — David Ellefson (@ellefsondavid) May 22, 2016



We all know the great and unique drummer that Nick Menza was, but he was also a trustworthy friend, a hilarious... https://t.co/Fyhj5aQ72o — Marty Friedman (@marty_friedman) May 22, 2016



Rest In Peace Nick Menza — Justis Mustaine (@Justis_Mustaine) May 22, 2016



Pictured below: Nick Menza on May 20