A Police composite of the person who was suspected of carrying a gun earlier today on the campus of Virginia Tech
A Police composite of the person who was suspected of carrying a gun earlier today on the campus of Virginia Tech, formally known as Virginia Polytechnic Institute and State University is seen on their website, August 4, 2011. Police described the suspect as being 6 feet (1.83 meters) tall with light brown hair and wearing a blue and white striped shirt, gray shorts and brown sandals. Authorities shut down the Virginia Tech campus for hours on Thursday after a report of a gunman at the university where 32 people were killed in a mass shooting in 2007. REUTERS

Three children reported a man walking outside on Virginia Tech's campus at 9:09 a.m. Thursday. The children said that he was holding a gun covered in a cloth.

Virginia Tech, located in Blacksburg, Va., suffered a shooting rampage in April 2007 that left 32 people dead and 25 injured.

Seung-Hui Cho, a 23-year-old English major, had a history of violent thoughts and behaviors and frightened professors but was allowed to roam free. The gunman mailed a manifesto of delusional letters, pictures, and video to NBC News prior to the shooting.

The man was described as six-feet tall, white, with light brown hair. He was wearing a blue and white striped shirt, gray shorts, and brown sandals. The seemingly suspicious man had no facial hair or glasses.

The university locked down until around 3 p.m. The following warning was posted on its website: "Person with gun reported near Dietrick. Stay inside. Secure doors. Emergency personnel responding. Call 911 for help."