Amalia Harte (center, with back to camera) hugs Samantha Westrum as Patrick Rice (right) holds a sign for Hugs for Hannah, an event sponsored by the Society for Awakening Souls held on the lawn at the University of Virginia on Friday. (Norm Shafer/For The Washington Post)

— Orange ribbons adorn lapels and backpacks throughout the campus here known as the Grounds, a reminder that the University of Virginia yearns for the return of sophomore Hannah Graham three weeks after she vanished in the night.

Anxiety over what befell the 18-year-old from Fairfax County, believed to be a kidnapping victim, grips the U-Va. community even as officials redouble efforts to protect students and provide counseling to those in need.

It is a jarring moment for the elite public university that founder Thomas Jefferson, the nation’s third president, envisioned as a tranquil “academical village” in a bucolic setting.

The alleged abduction followed two other widely publicized crimes against young women that occurred around here in the recent past: the abduction and death of Virginia Tech student Morgan Harrington, 20, after she attended a rock concert at a U-Va. arena in October 2009, and the death of U-Va. student Yeardley Love, 22, when an ex-boyfriend attacked her in a drunken rage in May 2010.

Harrington’s case remains unsolved. Her body was found in a field 10 miles south of here in January 2010. But the arrest of Charlottesville resident Jesse L. “LJ” Matthew Jr., 32, on a charge of abducting Graham with intent to defile, provided what police call a “new forensic link” in the earlier case, a link two people close to the investigation say is Matthew’s DNA.

John and Sue Graham, the parents of missing University of Virginia student Hannah Graham, released a statement Saturday begging for those who have information on their daughter's whereabouts to come forward. (City of Charlottesville)

Now this school of 23,000 students — a point of pride for Virginia and regarded among the nation’s best universities — is enduring a trauma with an unknown end. Claudia Kuchler, 19, a sophomore from Centreville, said Graham’s disappearance Sept. 13 cast a pall over the Grounds.

“You could feel it in the air, it was palpable,” Kuchler said late last week. “There was a gloomy aura over everything.”

Parties were canceled, she said, including a birthday celebration for Kuchler’s friend Alana Ama, 19, a sophomore from Falls Church. Instead they joined thousands at a candlelight vigil off the iconic Lawn in the first week after their classmate vanished.

Then Kuchler and Ama tried to figure out what to do next.

They stopped tuning in to social media after stories about Graham deluged the Internet, updates that felt overwhelming. The students — who, like Graham, live off the Grounds — also changed their routines. Once comfortable walking alone at night, they now go in groups and map out plans for bus or cab rides.

“Before, I never thought twice,” Kuchler said.

For university officials, the answer to what to do next is complex.

Hannah Graham timeline

They are tending to the worries of students, with special attention to those close to Graham, such as members of the school’s alpine ski club. They extended hours at the counseling and psychological services center, and they are planning to add staff there to handle a spike in requests for help.

They added a fourth safe-ride van to a fleet that ferries students in the dark when buses aren’t available. They convened a group of 17 administrators and students to scrutinize safety from top to bottom. That means a fresh look at where on the Grounds a stairwell or a parking lot might need more light, where off the Grounds a landlord might be urged to install a surveillance camera, and what could be gleaned about safety procedures from urban schools such as Johns Hopkins University in Baltimore and the University of Pennsylvania in Philadelphia.

They also are seeking to reassure parents, alumni and the wider world that Charlottesville remains not only a premier college destination, but also a secure one. Like 78 other U.S. schools, U-Va. is facing federal scrutiny for its handling of sexual violence reports amid a national focus on sexual assault on the nation’s campuses. Last year, the university police force recorded 15 reports of rape or forcible fondling, according to a 2013 Clery Act report. Charlottesville police have investigated 28 cases of rape or fondling so far this year, according to city data. The school hosted a national conference on the issue in February.

“U-Va. is as safe as we can make it,” university President Teresa A. Sullivan said in an interview with The Washington Post. “We continue to try to learn ways that we can make it safer. We are learning all the time.”

Sullivan, who teaches a class on labor markets that ends at 6:15 p.m. in Madison Hall, said she is keeping an eye on the autumn dusk. As days grow shorter, she has told her students: “I want to be sure you have a good way to get home.”

The president of a school founded nearly 200 years ago, famed for its architectural grace, cautioned against “overly romanticizing the idyllic aspects” of the U-Va. setting. “Let’s be real,” Sullivan said. “There are incidents that happen.” Indeed, Sullivan organized a dialogue on campus safety in September 2010 within weeks of taking office. That event was prompted by the Love murder. But the conversation has never really stopped.

Before Graham disappeared in September, many students were nonchalant about safety, said sophomore Morgan Phelps.

“People think that they are invincible and that ‘bad things are not going to happen to me’ and ‘I’ll be fine walking two blocks home alone at night,’ ” said Phelps, 19, of Chesapeake, Va. She lives in the same off-campus apartment building as Graham. “An event like this has really opened our eyes.”

Others, though, were already mindful of safety this fall because of a groundswell of national attention on prevention of sexual assault on campus.

Graham’s disappearance “has made students more conscious and aware of the ways that we can look out for one another,” said Sara Surface, 20, a junior from Richmond who is active in a campaign against sexual violence called Hoos Got Your Back. “Now more than ever people are reaching out to their friends [about] how they can be there through this rough time.”

For many here, one of the biggest challenges is that no one knows how long the rough time will last, or how it will end.

Allen W. Groves, U-Va.’s dean of students, said he remembers the 2:30 a.m. wake-up call from police with news about Love.

“You knew right away that something had happened, that it was bad and someone had died,” Groves said. The university’s student support team then mobilized in response to the death, standard practice for schools everywhere. Groves keeps a white ribbon pinned to the shade of a desk lamp in his office as a reminder of Love.

By contrast, there are no answers yet on Graham. An extensive and expanding search for her enters its third week Sunday.

On Saturday, Sue and John Graham, Hannah’s parents, thanked police and the university community for helping in that search and pleaded for more information that might lead to her whereabouts.

“We appeal to you to come forward and tell us where Hannah can be found,” the family said in a statement. “John has already said that this is every parent’s worst nightmare. That is true, but it is also a nightmare for our son, James, for Hannah’s grandparents and other members of our family, as well as for all of Hannah’s many friends here in Charlottesville and beyond. Please, please, please help end this nightmare for all of us. Please help us to bring Hannah home.”

For Jenna Van Dyck and Hallie Pence, two of Graham’s friends in the ski club, the tear-filled days since Sept. 13 have taken a toll.

Van Dyck, 20, who like Graham is from the Alexandria section of Fairfax County, and Pence, 21, of McGaheysville, Va., were with Graham in the hours before she was wandering the Downtown Mall and sending text messages indicating that she was lost and was looking for help. The two juniors were among the first to call police to report her missing.

“There’s a sense of numbness now,” Pence said. “We are exhausted. You could run yourself absolutely dry if you let everything get to you.”

Van Dyck said the tight-knit ski club, which has 439 members, is beginning to prepare for the worst.

“Whenever I hear a siren, it makes me hopeful that they could be responding to something for Hannah,” Van Dyck said. “But gaining closure would be a relief at this point.”

Van Dyck and Pence are edging back into the college routine. Van Dyck said that she’s beginning to pay more attention in class, instead of losing focus because of her worries about Graham, and that she’s once again sleeping through the night.

Among friends, Van Dyck and Pence said, they tend to ask, “How are you doing?” rather than “Are you okay?”

“Because no one is okay,” Pence said.

Professors are handing out orange ribbons to wear as tokens of solidarity with the missing student, said Abraham Axler, 19, president of the Class of 2017.

Students in recent days also have been sending thank-you notes to Charlottesville police and search-and-rescue teams working to find Graham. “Bring Hannah Home,” a message that her friends painted on the landmark Beta Bridge, still greets people walking to and from class. But as days pass, Axler said, the outlook appears more grim.

“There’s getting to be a lot of frustration,” said Axler, who’s from New York. “There’s a lot of questions, and it’s wearing people down.”

Lani Galloway, 20, a senior from McLean, was among a group of U-Va. students, including Graham, who spent last spring break helping rebuild homes after tornados hit Tuscaloosa, Ala. She said Graham showed poise with a circular saw and meticulous attention to detail. “She gave it her all,” Galloway said.

Galloway walks around town with a pink bottle of pepper spray hooked to a key chain, which she bought after hearing about some stabbings that occurred last summer near the school.

Galloway said she was shaken by news of the forensic link between Graham’s case and the investigation into Harrington’s death.

“Knowing there’s a connection puts an idea into your head that you don’t want to think about,” Galloway said. “I’m scared for her.”

A few days ago, a reminder popped up on Galloway’s cellphone for a date she and Graham had long planned. They wanted to see a movie based on a novel they had both read about a woman who mysteriously vanishes.

The film, in theaters this weekend, is “Gone Girl.”

Anderson reported from Washington.