The Who founding member John Entwistle’s death was accidental, but it was caused by a “heart attack we believe was brought on by the significant amount of cocaine” in his system, according to Clark County coroner Ron Flud, the Associated Press reports. Entwistle was found dead in his bed at Las Vegas’s Hard Rock Hotel on June 27, one day before the band was scheduled to kick off its national tour. How much of the drug the bass player had consumed is not known, said the coroner, citing the fact that Entwistle, 57, suffered with a pre-existing heart condition for which he took medication. “Cocaine is a different animal,” Flud explained. “It’s not like alcohol. There’s no way we can put a number on it. You’ve got a lethal drug on board at the time you have a bad heart. That’s a bad combination.” Hard Rock officials, as well as representatives for The Who’s label, MCA/Universal Music Enterprises, declined comment to AP on Thursday. Vegas District Attorney Stewart Bell told the news service that he did not anticipate criminal charges being filed against anyone in connection with Entwistle’s death. “From a legal point of view, there isn’t anything to be done because we don’t have anybody else who might be responsible,” he said.