An antique 850-pound brass bell was installed on a limestone rostrum for the occasion, and 33 white balloons were released into the air 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 released.

"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."

The chimes of the bell echoed through the campus, covered with a week's worth of memorials and tributes to the students, including flowers, writings and candles.

The 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.

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

"I thought last week as time goes by that I could forget this tragic incident," graduate student Sijung Kim said. "But as time goes by I find I cannot forget."

"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."

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.

In front of the dorm, a small marching band from Alabama played "America the Beautiful" and carried a banner that read, "Alabama loves VT Hokies. Be strong, press on."

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."

University officials were not sure how many students planned to be back Monday. 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."

Former roommates described Cho as methodical and deliberative, recalling that he appeared to research women who he was later accused of stalking. Computer analysis could show whether Cho performed such research on his victims.

Dr. William Massello, the assistant state medical examiner in Roanoke, said Cho died from a self-inflicted gunshot wound to his head after firing enough shots to wound his victims more than 100 times.

Meanwhile, Virginia Tech's Student Government Association issued a statement Sunday asking the news media to respect the privacy of students and leave campus. Around campus, camera crews and reporters are routinely met with scorn, including comments such as "go home."

Around campus are constant reminders of counseling options, and state police will provide security at least through Monday.

"I still feel safe. I always have," said Claire Guzinski, a resident of West Ambler Johnston Hall, where Clark and Hilscher were slain. "I just think, stuff happens. It's still in the middle of nowhere, a rural area. What are the chances of it happening twice?"

The only thing she feels nervous about, she says, is what to say to classmates who lost close friends.

"What do you say?"