“How could this happen?” For many, that was the inevitable question Tuesday in response to the news that Dana Reeve, the sunny and vibrant widow of Christopher Reeve, had died of lung cancer at the stunningly young age of 44.

“While it is the more the more unusual scenario that someone who never smoked would develop lung cancer, 10 to 15 percent of the cases do occur in non-smokers,” says CBS News health correspondent Emily Senay.

“One of the major problems is, by the time it’s detected, it’s often quite far advanced.”

“What I didn’t know is that lung cancer is the number-one cancer. We’re always looking for breast and ovarian and uterine, and I’m a non-smoker, and I live in the country, so I think ‘I’m good,’ so I was completely shocked,” she told “Entertainment Tonight” interviewer Kathie Lee Gifford. (”ET” is also part of CBS, Inc.)

Source: CBSNews