April 16 (Bloomberg) -- A gunman at Virginia Tech University carried out the deadliest shooting rampage in U.S. history today, killing at least 32 students and faculty before turning the gun on himself.

An additional 28 people were hospitalized with gunshot wounds and other injuries. Police declined to identify the victims at the university in Blacksburg, Virginia, the state's largest. A preliminary identification of the gunman has been made, though his name hasn't been released, police said.

``I'm at a loss for words to explain or understand the carnage that has visited our campus,'' university President Charles Steger said at a televised press conference from the school, about 270 miles (430 kilometers) southwest of Washington.

Governor Tim Kaine, in Tokyo, canceled a trade visit today and boarded a plane for Virginia. The U.S. House of Representatives observed a moment of silence.

``Today our nation grieves with those who have lost their loved ones at Virginia Tech,'' President George W. Bush said at a White House news conference.

U.S. Education Secretary Margaret Spellings said her department is working with the White House and other agencies to identify resources that can be provided to Virginia Tech.

The college is offering counseling for students, faculty and staff, and will hold a public gathering at Cassell Coliseum at 2 p.m. tomorrow, according to a statement on its Web site.

Delayed Warning

The first two victims were killed at about 7:15 a.m. local time at West Ambler Johnston dormitory, Virginia Tech Police Chief Wendell Flinchum said. Police said they didn't close the campus because they believed it was an isolated incident and the shooter had left the grounds.

``We secured the building, we secured the crime scene,'' Flinchum said. ``You can second guess all day. We acted on the best information we had.''

At 9:29 a.m., the university sent an e-mail warning students that a gunman was on the loose and to stay indoors. At about 9:45 a.m., a shooter opened fire at the engineering school's Norris Hall, killing 30 people. Several students leapt to safety from upper stories, and the gunman's body was later found at the building, Flinchum said.

He was armed with two pistols and multiple clips of ammunition, the Associated Press reported, citing unidentified law officials. Police are trying to determine if the same person was responsible for both incidents.

At a second press conference, Flinchum said ``a person of interest'' related to the dorm shooting had been identified, but not charged with a crime. That person, who knew one of the victims at the dorm, isn't in custody, Flinchum said.

Police have a ``preliminary'' identification for the Norris Hall shooter, said Flinchum, who declined to give more details.

Bloodiest Attack

Law enforcement officials said the massacre was the bloodiest in U.S. history, surpassing the two dozen killed in Killeen, Texas, in 1991. In that attack, George Hennard drove his pickup truck into a restaurant and shot 23 people to death before killing himself.

Across the Virginia Tech campus, students and faculty locked themselves inside buildings for hours as police tried to determine whether another shooter was involved. The campus was closed and will reopen at 8 a.m. tomorrow, according to the college's Web site. Classes were canceled today and tomorrow.

``This is a rural area, a college town,'' student Austin Eckerd, 21, said in an interview. ``You usually think of these things happening in downtown Baltimore or in Washington.''

Seventeen people were treated at Montgomery Regional Hospital. Five were taken to Lewis-Gale Medical Center; four to Carilion New River Valley Medical Center, and two to Carilion Roanoke Memorial Hospital, HCA Inc. said in a statement. Two of the five at Lewis-Gale were in surgery.

Bomb Threats

The attack came a week after bomb threats were made at Virginia Tech, formally called Virginia Polytechnic Institute and State University. The school has about 26,000 students.

``The bomb alerts on Friday were all focused on the engineering building, and now the shootings today,'' Tyler Henderson, 20, a sophomore at the college, said in an interview. `` I don't understand why this would happen here. It's horrifying. This is a beautiful campus and has a great atmosphere. When I walked to class, everything was normal.''

Today's attack renewed calls by gun-control advocates for limits on the sale of firearms. White House spokeswoman Dana Perino said while Bush ``believes that there is a right for people to bear arms,'' all laws must be followed.

``Mass shootings have come to define our nation,'' Josh Sugarmann, executive director of the Violence Policy Center, said in a statement. ``These tragedies are the inevitable result of the ease with which the firepower necessary to slaughter dozens of innocents can be obtained.''

Columbine Echoes

The incident was the second fatal shooting near Virginia Tech in eight months. In August, an inmate escaped a hospital and killed a police officer and security guard. The accused gunman, William Morva, has been charged with murder.

Today's attack also evoked memories of the 1999 massacre at Columbine High School in Littleton, Colorado, where two students killed 13 people before turning the guns on themselves.

``I can imagine what they're going through,'' Frank DeAngelis, Columbine High principal for almost three decades, said in a telephone interview. ``You're hoping there would be lessons learned from Columbine, but that's obviously not the case.''

To contact the reporter on this story: Demian McLean in Washington at dmclean8@bloomberg.net.

Last Updated: April 16, 2007 20:21 EDT