Investigators have reportedly ruled out drugs as a factor in the death of former Megadeth drummer Nick Menza.

TMZ reports that "law enforcement sources" have shared autopsy results indicating that the 51-year-old drummer did not succumb to a "stereotypical drug-related death." Instead, after conducting a search and interviewing people close to Menza, they've reached the conclusion that he'd been sober for close to a decade, and his system was clean when he suffered a fatal heart attack on May 21.

As previously reported, Menza was performing with his band Ohm in Studio City, Calif., when he appeared to have a seizure on the stage. Patrons at the venue administered CPR until an ambulance arrived, but neither they nor the EMTs on the scene were able to revive him.

A number of Menza's peers and former bandmates have shared their grief via social media, led by Megadeth frontman Dave Mustaine, who expressed stunned disbelief after receiving word of his passing. Saying he learned of Menza's death upon waking up to a text message from his son, he told followers, "Shocked, devastated and saddened don’t begin to describe my feelings."

Mustaine has outlined plans for a benefit concert in honor of Menza, during which he hopes to gather as many former Megadeth members as possible. "We’re working out the details," said Mustaine. "We’re hoping to leave an open stage for all of the alumni for Megadeth to come there and play with us, so that we can help leave behind something for Nick’s children, which I think had been kind of left in a bad way. We wanted to get all that stuff set up and right now the wheels are all turning in our camp."

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