Every day, nearly 2,500 missing-persons reports are filed across the United States.

Few of those reports receive any media attention. Yet the disappearance of Virginia Tech student Morgan Dana Harrington went from local newspaper and television stations to cable television's "Nancy Grace" in 48 hours.

According to some television and digital journalism experts, Harrington's case skyrocketed because of a confluence of circumstances including her connection to the site of the largest mass school shooting in U.S. history.

Those experts say that the disappearance of the 20-year-old from Roanoke County made national news because:

-- Harrington is a young, pretty, blue-eyed woman, not unlike other missing females whose disappearances have received widespread media coverage in recent years.

-- The fact that she disappeared from a Metallica concert in Charlottesville on Saturday lends a national element to the story. Metallica, one of the most popular heavy metal rock bands of all time, featured a posting on its Web site headlined "One Of Our Fans Is Missing."

-- Social networking Web sites such as Facebook and Twitter spread the news quickly among users nationwide.

-- Harrington is a student at Virginia Tech, a place that many Americans still associate with the mass shootings of April 16, 2007.

The Virginia Tech connection may be as important as any factor in making Harrington's disappearance national news, said Robert Thompson, one of the country's most-respected media experts and the founding director of the Bleier Center for Television and Popular Culture at Syracuse University.

"Part of this is when you think 'Virginia Tech,' it carries certain sacred overtones to the country," Thompson said. "Not only do you have a young college student in danger, but when you attach the words 'Virginia Tech' ... Virginia Tech is one of those sets of words like '9/11' and 'Oklahoma City.' It means more than just the college name.

"The whole country has strong sympathy and empathy for the university. It's still recent in their minds, the last big national story to happen there."

Claudette Artwick, an associate professor of broadcast and digital journalism at Washington and Lee University in Lexington, agrees that Harrington's looks and her connection to Tech probably have contributed to the national media's interest. However, the Internet also has played a huge role in making the story too big to ignore, she said.

"Social media are a huge part of young people's lives," Artwick said. "Everybody's tweeting about it, not only people who know her. Who's the reporter and who's the source anymore?"

The Associated Press story about Harrington's disappearance, which included a photograph, was picked up by most major newspaper and television Web sites Wednesday. Harrington's disappearance was among the top five most-viewed stories on CNN.com's Web site for much of the day.

Artwick also notes that Harrington's parents, Dan and Gil Harrington, were quick to reach out to national media to draw attention to their daughter's disappearance and to ask for help finding her. Gil Harrington was interviewed by telephone on HLN's "Nancy Grace" on Tuesday. Grace, a former special prosecutor from Georgia, covers legal issues and crime on her show, HLN's top-rated program.

In a video clip posted on the CNN.com Web site, Grace described Morgan Harrington as "beautiful on the inside as well as the outside. She looks like a fairy princess." While speaking to Gil Harrington, Grace choked up when she spoke of her own young daughter and the thought of someone "making off with her."

Grace's show, as well as other cable news programs, have been criticized for past excessive coverage of missing white females who are young and pretty, but not covering disappearances of minority women or missing men. TV and social critics have referred to such coverage as "Missing White Woman Syndrome."

However, several law enforcement agencies have credited shows such as "Nancy Grace" for keeping missing-person cases in the news and for helping them solve some cases.

Plus, as Thompson said, the disappearance of a young person "is every parent's worst nightmare," regardless of race or sex.

The National Center for Missing Adults, a nonprofit organization that acts as a clearinghouse for information about missing adults, reports that nearly 2,500 missing-persons reports are filed every day. The FBI's National Crime Information Center reported 102,764 active missing-person records at the end of 2008.

When a story makes the national news, you can expect it to be covered for a while, Thompson said.

"Once it makes 'Nancy Grace,' it's almost unstoppable," he said.