Thousands of Virginia Tech students and faculty filled the center of campus Monday to pay solemn tribute to the victims of last week's massacre — listening quietly as a bell tolled for the dead on the day classes resumed at the grief-stricken school.

An antique 850-pound brass bell was installed on a limestone rostrum for the occasion, and 33 white balloons were released in memory of the 32 victims and the gunman, Seung-Hui Cho. About 1,000 balloons in Virginia Tech colors — maroon and orange — were also set free.

"I've been back with my friends, but I don't know how it's going to feel, seeing the empty seats in the classroom, noticing the people who aren't here anymore," said David Patton, a 19-year-old freshman who was friends with two victims. "I'm wondering where they are now, if they are in heaven, and when I'll see them again."

As classes resumed Monday, counselors and university staff were dispatched throughout campus, wearing special name tags and armbands to indicate they were there to help. University officials said they have seen a range of emotions among the students.

"We are seeing the resolute, the angry, the confused, and the numb," said Ed Spencer, the associate vice president of student affairs.

Officials said class attendance averaged about 75 percent, and between 85 percent and 90 percent of students are still living in their dorms. The university also said that the rampage has dissuaded few prospective students from wanting to attend Virginia Tech.

"We got 12,848 offers of admissions, so far we've heard from five who've indicated those offers will be declined as a result of this," said school spokesman Larry Hincker.

Officials are also seeing many signs that things were returning to normal. "The same students who sit in the last row are still nodding off in class," Mark McNamee, the Virginia Tech provost.

Another painful question is how to proceed with the classes where students and professors were murdered last week. Officials said students and department heads gathered to talk about how to go forward for the remainder of the semester.

A week after the shootings, the campus was covered with memorials and tributes, including flowers, writings and candles.

The memorial bell rang at 9:45 a.m., around the time when Cho killed 30 students and faculty members in a classroom building before committing suicide. The tribute lasted 11 minutes, as the bell rang for each of the victims and Cho.

"It's only been a week, but it seems so long ago," said Marc Hamel, 43, a political science student. "Getting back into class is really going to help."

As the crowd broke up, people started to chant, "Let's Go Hokies" several times.

A moment of silence was also observed at about 7:15 a.m., near the dormitory where Cho's first victims, Ryan Clark and Emily Hilscher, were killed.

Afterward, a group of students and campus ministers brought 33 white prayer flags from the dorm to the school's War Memorial Chapel. They placed the flags in front of the campus landmark and adorned them with pastel-colored ribbons as the Beatles' song "The Long and Winding Road" played through loudspeakers.

"You could choose to either be sad, or cheer up a little and continue the regular routine," said student Juan Carlos Ugarte, 22. "Right now, I think all of us need to cheer up."

Ugarte, a senior from Bolivia, wrote a message on a yellow ribbon for one of the victims, Reema Samaha. "God will forever be with you. I will always pray for you, and remember."

Andy Koch, a former roommate of the gunman, was among the many students who remembered the shooting Monday. "Last night, I didn't sleep much," he said.

On the main campus lawn stood a semicircle of stones — 33 chunks of locally quarried limestone to remember each of the dead.

Someone left a laminated letter at Cho's stone, along with a lit purple candle.

"Cho, you greatly underestimated our strength, courage and compassion. You have broken our hearts, but you have not broken our spirits. We are stronger and prouder than ever. I have never been more proud to be a Hokie. Love, in the end, will always prevail. Erin J."

Virginia Tech is allowing students to drop classes without penalty or to accept their current grades if they want to spend the rest of the year at their parents' homes grieving last week's campus massacre.

But whatever decisions they make academically, many students say they will do their mourning on campus — and that they can't imagine staying away now.

Students began returning to campus as police continued their investigation. State Police investigators still had not connected Cho to his victims but were reviewing data, including Cho's computer files, looking for such a connection.

"We're going back to the hard drives," State Police spokeswoman Corinne Geller said. "They're still in the processing and analysis stage."

Police have pulled from the university server all e-mails to and from Cho, as well as e-mails to and from Hilscher, the first victim, according to court documents filed Monday. Police also recovered other e-mail logs and Cho's personal cell phone records.