Shortly after noon Thursday, a gunman shot and killed a campus police officer at Virginia Tech. Police now believe a second body found in a nearby parking lot may've been the gunman.
Officer Deriek Crouse, 39, was making a routine traffic stop along a main street that runs through campus.
Witnesses said the gunman -- who police believe was not in the car being pulled over -- shot and killed the officer, then fled on foot toward what's called "the cage" -- a parking lot for freshman and other students.
A second shooting victim was found dead in the parking lot. In a press conference later Thursday, authorities could not confirm whether this was the gunman, but did say a weapon was found.
Freshman student Juliet Felding witnessed the horrific scene.
"The police pulled up and opened his car door," she recalled. "When they opened it up, he fell out toward the ground. I could see his face. He was covered in blood."
Virginia Tech sent out a campus alert telling students to stay indoors. Visitors were ordered to stay off campus.
CBN News spoke with one student just moments after the alert went out.
"I was in an engineering building at the time," the student said. "They moved us into an interior conference room. All the doors are on lockdown outside. And now there are a lot of different rumors going around as to updates."
Thursday's event was the most extensive campus lockdown at the university since the 2007 shooting rampage that killed 32 students and faculty.
That incident prompted the school to revamp its emergency alert system.
The university added text messaging, emailing and voicemail to warn students of danger on campus.
The new system was used in the latest event and students say, for the most part, everyone remained calm.
Virginia Tech's campus has grown substantially over the past decade, but is located in a fairly rural part of Virginia. The school also sits at the intersection of an interstate and major highway.
Thursday's violence came one day before final exams are set to begin for students.