Former Megadeth drummer Nick Menza, who played on many of the metal band’s successful albums in the 1990s, died Saturday (May 21) after collapsing on stage during a concert. He was 51.

Menza was playing with his new band Ohm at the The Baked Potato in Los Angeles when he suddenly collapsed during third song of the performance, CNN reports. Paramedics could not revive him. 

The suspected cause of death was a massive heart attack, J. Marshall Craig told the Associated Press. 

The 51-year-old died at the club of a suspected massive heart attack, Craig said.

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

Menza was Megadeth's longest-serving drummer, performing on five records over nine years, including Rust in Peace, Countdown to Extinction and Youthanasia. His death came as a shock to Megadeth frontman Dave Mustaine.

“Tell me this isn't true,” Mustaine tweeted Sunday. “I woke at 4 AM to hear Nick Menza passed away on 5/21 playing his drums w/Ohm at the Baked Potato.”

Ex-Megadeth guitarist Marty Friedman called Menza a “great and unique drummer” and a “hilarious bandmate” in a Facebook post Sunday. “I’m beyond sad, did not see this coming at all. RIP Brother."

After leaving Megadeth in 1998, Menza pursued an interest in jazz and became an accomplished woodworker.

Menza's autobiography, co-written by Craig, will detail the drummer's life in and out of music and is set for a July release.