when you have runaway high blood pressure and fail to get it under conrol.
I saw The E Street Band at The Stone Pony years ago,I never liked Srpingsteen but "The Big Man" had a mastery of the sax that could put you in another place/time.
....but was still very shocked to hear that he had passed. I wouldn't say I'm a huge fan of Springsteen's music, though I think he's a great lyricist and I respect his integrity tremendously. But Clarence -- rarely does one person define a band's sound the way he did, especially when that one person isn't a guitar player. I can't imagine how they're going to go on without him. They can't just hire another sax player.
My condolences to his family, friends and bandmates. What a huge loss.