LAS VEGAS (AP) - John Entwistle, the bassist for the rock band The Who, was found dead Thursday in his hotel room of an apparent heart attack. He was 57.

Entwistle, a founding member of the band, stood out because he played without emotion, a stark contrast to the antics of lead guitarist Pete Townshend and lead singer Roger Daltrey.

The group was scheduled to play at the Hard Rock Hotel-Casino on Friday, the first date of a three-month, nationwide tour. The Vegas show was canceled but the rest of the tour was undecided, said Beckye Levin of promoter Clear Channel Entertainment.

"I was told he passed away in his sleep last night," Levin said, breaking into sobs during a telephone interview.

Who manager Robert Rosenberg said he was "saddened and shocked."

There was "nothing suspicious" about Entwistle's death, Clark County fire spokesman Bob Leinbach said.

The group, founded in London in the early 1960s, was part of the British rock invasion and the voice of a new breed. Their concerts were literally explosive - a fusion of audacious acrobatics, martial precision and high octane rock 'n' roll that blew away audiences and left the stage and their instruments a smoldering wreck.

The group's albums included "My Generation," "Happy Jack," "The Who Sell Out," "On Tour: Magic Bus," "Live at Leeds," "Who's Next," "Meaty, Beaty, Big and Bouncy," "Quadrophenia," "Odds and Sods," "The Who by Numbers," "Who Are You," "The Kids Are Alright," "Face Dances," and "It's Hard." They also made the groundbreaking rock opera film, "Tommy," starring Ann-Margret, in 1975. The group's wild exploits were legendary. During a concert at the Rikki Tik Club in England in May 1966, Townshend smacked Entwistle in the head with his guitar; a year later, drummer Keith Moon, at the close of the band's performance on "The Smothers Brothers Comedy Hour," detonated a flash bomb that destroyed his drum set, stunned guests and damaged Townshend's ears.

Moon - the band's original drummer - lived life on the edge, right up until his untimely death in 1978 in his London apartment at age 31 from an overdose.

The remaining members of the band retired in 1982 after a concert in Toronto, but they reunited and had toured frequently in recent years. They gave a rousing performance at last year's "Concert for New York," which raised funds for the victims of the Sept. 11 attacks.

They were inducted into the Rock and Roll Hall of Fame in 1990.