Virginia Tech is on lockdown as police search for a possible gunman.

“We have not had any reported sightings or any more information regarding this person,” Tech Police Chief Wendell Flinchum told reporters at a news briefing Thursday morning.

“We’re in a new era. Obviously this campus experienced something terrible four years ago... Strictly, as an abundance of caution, we are going to keep the campus under alert status,” said Virginia Tech spokesman Larry Hincker.

A shooter killed 32 people in the Virginia Tech shooting in 2007. April 16, 2011 marked the four year anniversary since the shootings.

Those who died in April of 2007 include (as reported by CBSNews):

Ross Abdallah Alameddine, 20 of Saugus, Mass., according to his mother, Lynnette Alameddine.
Christopher James "Jamie" Bishop, 35, taught German at Virginia Tech and helped oversee an exchange program with a German university.
Brian Bluhm, 25, a master's student in water resources, received his undergraduate degree in civil engineering at Tech and was getting ready to defend his thesis.
Ryan Clark, 22, a student from Martinez, Ga., was a fifth-year student working toward a triple-degree in psychology, biology and English and carried a 4.0 grade-point average.
Austin Cloyd, 18, a freshman, was an international studies major. She moved to Blacksburg for her senior year in high school; her father is C. Bryan Cloyd, a professor of accounting and information systems at Virginia Tech.
Jocelyne Couture-Nowak, a French instructor at Virginia Tech, was instrumental in the push to create the first French school in Truro, Nova Scotia, where she lived in the 1990s with her husband, Jerzy Nowak.
Peruvian student Daniel Perez Cueva, a 21-year-old international relations major, was killed while in his French class, said his mother, Betty Cueva.
Prof. Kevin Granata, 46, researched muscle and reflex response and robotics.
Mathew Gregory Gwaltney, 24, of Chesterfield, Va., was on the brink of finishing his master's degree in civil and environmental engineering, and planned on returning to his hometown of Chester, Va., to be near his parents.
Caitlin Hammaren, 19, of Westtown, N.Y., a sophomore majoring in international studies and French.
Jeremy Herbstritt, 27, was a graduate student in civil engineering from Bellefonte, Pa.
Rachael Elizabeth Hill 18, was a graduate of Grove Avenue Christian School in Henrico County and was a freshman at Virginia Tech.
Emily Jane Hilscher, a 19-year-old freshman from Woodville and an animal and poultry sciences major, was known in rural Rappahannock County as an animal lover.
Jarrett Lane, 22, of Narrows, Va., a senior majoring in civil engineering, liked Christian Alternative music, "The Simpsons" and "ESPN Sports Center."

To see a continued list and full description of the 2007 victims, click here.

Watch a video made for YouTube in memory of the 2007 victims:

Must Read?Virginia Tech Lockdown Brings Back Ghost of 2007 Shooting