Students and faculty returned to class at a Nevada middle school Monday for the first time since a 12-year-old boy fatally shot a teacher in the schoolyard one week ago.
A large contingent of police were on hand to meet the students, family and staff as classes resumed at Sparks Middle School in Sparks, Nev.
Mathematics teacher and former U.S. Marine Michael Landsberry, 45, was shot in the chest by a seventh-grader who also wounded two students during Monday's attack before taking his own life.
The boy is thought to have brought the gun, a Ruger 9mm, from his home, Sparks Deputy Police Chief Tom Miller said.
The two students wounded in the shooting were transported to a local hospital and are recovering.
Some students speculate that bullying may have played a role in the shooting, but police say they have no evidence of that and have refused to comment about anything that might have provoked the attack, the Associated Press reports.
Landsberry was taking his turn greeting middle schoolers as they headed into class after a week-long fall break when the shooting started, students told the Reno Gazette-Journal.
"We know the healing process is going to take a long time," Washoe County School District Superintendent Pedro Martinez told the newspaper.
"It's not all going to happen today," Martinez said. "Today is a beginning."
NBC's Matthew DeLuca contributed to this report.