Blacksburg, Va. — Thousands of students streamed onto Virginia Tech’s Drillfield for a memorial service this morning for the 32 students and faculty members who were killed here exactly one week ago.

Classes have resumed, and the campus is bustling again. But the Drillfield was virtually silent, despite the large crowd of maroon-and-orange-clad students and other mourners. Those who were talking did so quietly.

A bell had been brought out to the edge of the field, where an arc of small limestone memorials to the 32 victims and the gunman has drawn a steady stream of visitors. The bell was rung once at 9:45 a.m., the time Seung-Hui Cho began his attack in nearby Norris Hall. Some students flinched as the loud ringing broke the quiet on the field.

After a minute of deeper silence, the bell was rung at brief intervals for each victim. A white balloon was released each time it tolled.

Students remained transfixed during the ceremony, which lasted several minutes. At its conclusion, officials released 1,000 maroon and orange balloons. At 10 a.m., an impromptu cry of “let’s go, Hokies” rang out several times.

The students drifted slowly away, speaking softly to one another or on cellphones to friends and parents. One young woman complained about an exam her professor had scheduled for this afternoon.

Earlier this morning, another silent ceremony was held near the dormitory where the first two student victims were killed. —Paul Fain