It’s a situation Nora Ephron might have found the humor in: She could have read her own obituary. Not that she did — Ephron was reportedly ”gravely ill” when Liz Smith, writer for wowOwow, posted her appreciation of Ephron before she actually died (the post has since been removed). Shortly after Smith’s story was posted, the New York Times confirmed through Ephron’s publisher, Knopf, that she was still alive. Ephron died later that night of complications from the blood disorder myelodysplasia.

View Photo Gallery: Ephron, who emerged over the past four decades as one of America’s warmest and most acute chroniclers of contemporary culture and society, has died.

Smith’s gaffe put Ephron in an exclusive group of notable people whose deaths have been mourned too soon — even if it’s only by a matter of hours. Twitter rumors about celebrity deaths often stir the pot, but it’s an entirely different matter when a news outlet publishes an obituary early. Bob Hope died at age 100 in 2003, but his obituary was mistakenly published in 1998 on the Associated Press’s Web site. In one 2003 incident, CNN inadvertently published premature obituaries of several notables, including Vice President Dick Cheney, Pope John Paul II, Nelson Mandela and Fidel Castro, among others. In 2001, the London Telegraph’s obituary editor printed an epic and humorous apology for “killing off” Dorothy Fay Ritter, the widow of the singing cowboy Tex Ritter and mother of actor John Ritter.

Fast-moving and confused events can cause journalists to deploy an obituary too soon — when Rep. Gabrielle Giffords was shot in January 2011, many news organizations had to retract reports that she was dead. More recently, several news outlets reported the death of Penn State football coach Joe Paterno a day early.

For many celebrities and notable people, The Post prepares obits well in advance, as do many other news outlets (sometimes, so far in advance that the writer of the obit has died before the subject, as in The Post’s Gerald Ford obituary) . The Post did not have an obit prepped for Ephron, however, and obituary editor Adam Bernstein began writing her obit yesterday morning, when he learned she was failing.

The Post confirms deaths through wire services or other reputable news organizations, or through family members or officially designated spokespeople, such as managers.

“We were fortunate that [Washington Post columnist] Richard Cohen is a really good friend [of Ephron],” said Bernstein. When Bernstein heard that Smith had put her appreciation up, “I just called Richard. He was standing outside her hospital room, and he said, ‘No, she's not.’ ”

Of course, when it comes to the premature publication of Smith’s story, most journalists’ reaction is: There but for the grace of God go I . ‘To criticize other news organizations is like asking for your own comeuppance,” said Bernstein.

Matt Schudel, a Post obituary writer, and Bernstein said that they couldn’t recall an instance when a Post obituary went up too soon, but an obituary photo gallery for John Wooden, basketball coach at UCLA, was posted online a few days before the legendary coach’s death at age 99 in 2010, and it “caused some embarrassment,” said Schudel. “It's sort of the cardinal sin of obituary writing.”

“There’s this insatiable demand for news, but Twitter and social media don't have the backstops that publications do,” said Bernstein. And print publications are glad they have those backstops: “Our credibility is always on the line.”