It was only one thin and sinewy story thread out of hundreds stitched into the body of one of television's longest-running and most successful prime-time dramas. On last week's "ER," a stampeding holiday shopper didn't get the designer handbag she sought, but she did leave with a soccer ball-size ornamental star lodged in her right side.

Gallows humor is an "ER" storyline staple, one that highlights one of the show's most persistent undercurrents — everyone, including on occasion a star, dies.

The show tied for the most Emmy nominations in television history also might hold the record for its highest body count. Nearly every week, at least one patient is killed off. The more mundane or freakishly random, the better. That's life on "ER," the founding principle of which was to offer a documentarian's view of a teaching hospital in a major urban area. Even the show's doctors, who have been felled by brain cancer, roadside bombs and plummeting helicopters, are not immune from fatal calamity.

Everyone dies. That is, except the show itself. In its 13th season, "ER" amazingly has defied television's cruel actuarial tables, which if anything in recent years have become even crueler. "ER" long ago should have joined "Chicago Hope" and "City of Angels" in the medical show graveyard, but instead it's acting like the teenager it is: vital, robust and fond of railing about the issues of the day. It's a car crash with a social conscience — some critics might say a bleeding heart — but one in which a sizable audience isn't ready to let go quietly into that good Thursday night.

"With the state of affairs within the country, I think we're a place that feels safe for people," said John Stamos, who became a show regular this season as a Gulf War paramedic who wants to become a doctor. "For a lot of people, it's like coming back home."

For executive producer John Wells, a revived "ER" continues to animate a prolific and stellar TV career that includes work on such shows as "China Beach" and "The West Wing." As one of the program's original executive producers and a frequent director, Wells can take special joy in its recent, perhaps mysterious, re-entry into the American conversation.

"Initially, we really had to fight against this idea that audiences wouldn't want grimy medicine," Wells said. "But I think 'ER' has shown they don't want some sanitized version. They want the truth of it."

Last season, it appeared that "ER" was once again nearing its end. Until just last month, NBC had planned to place the show on a three-month hiatus beginning in January to showcase a new drama called "The Black Donnellys" in the same highly coveted Thursday time slot.

Certainly, NBC's plans were not good news for a show that has amassed 22 Emmy Awards and 117 Emmy nominations, tying it with "Cheers" as the all-time leading nominee in any genre.

"We really felt like we were being put out to pasture," said David Zabel, a former staff writer who became one of the show's executive producers and now runs the show on a day-to-day basis.

To some, such a move was long overdue. But, thanks in part to riveting cliffhangers that closed last season and opened this one, the show's pulse continued to beat as strong as that of an endurance athlete. This season the show usually ranks first in its time slot with original episodes, averaging about 13.9 million viewers (compared with 13.8 million last year).

Last year, the show's lead-in was "The Apprentice," and despite losing it this season, it's gained ground in a climate where merely holding it is considered a triumph. Indeed, on the strength of its strong performance, not only did NBC ditch the "ER" hiatus plan, but it also has ordered an extra Christmas episode.

"What you're seeing this year is the audience doesn't like the new flavors being offered by our competitors," said Kevin Reilly, president of NBC Entertainment. "They're finding the old flavor is pretty damn good."

Of course, "ER" always has served up new flavors for viewers. None of the original major cast members remain from the first season. The show has thrived despite enduring the loss of more than a dozen main stars in its ensemble cast. The most life-threatening was when George Clooney, TV's McDreamy of the '90s, left after the fifth season.

"People were extremely nervous when George was leaving. They thought this would be it for the show," said Laura Innes, who began portraying Dr. Kerry Weaver in the second season, making her the show's senior major cast member. "But when we survived that, everybody kind of said, 'Oh, maybe this is a different kind of beast.' "

The revolving door of big-name exits forced the show to evolve or die, and that as much as anything may be responsible for its longevity.