Until today, the deadliest campus shooting in U.S. history took place in 1966 at the University of Texas, where Charles Whitman climbed to the 28th-floor observation deck of a clock tower and opened fire. He killed 16 people before he was gunned down by police.

Columbine comparison
In the Columbine High School bloodbath near Littleton, Colo., in 1999, two teenagers killed 12 fellow students and a teacher before taking their own lives.

The locations
On the 2,600-acre Tech campus, the shootings took place at West Ambler Johnston, a co-ed dorm that houses close to 900 people, and Norris Hall, an engineering building.

The fallout
After the shootings, all entrances to the campus were closed. The campus was to reopen Tuesday, but classes were canceled.

Recent threats
Police said there had been bomb threats on campus over the past two weeks but said they have not determined any link to the shootings.

Second closure
It was second time in less than a year that the campus was closed because of a shooting.

President Bush
"He was horrified and his immediate reaction was one of deep concern for the families of the victims," a spokeswoman said. She said federal assistance is available if Virginia authorities request help. -- Staff and Wire Reports

In August, the opening day of classes was canceled and the campus closed when an escaped jail inmate allegedly killed a hospital guard off campus and fled to the Tech area.