Federal law enforcement officials say at least 33 students are dead, including the gunman, who opened fire Monday on the campus of Virginia Tech.

The first 911 call came in to the campus police department at 7:15 a.m. concerning an incident at West Ambler Johnston, a residence hall, and that there were multiple shooting victims.

While that investigation was underway, a second shooting was reported in Norris Hall, located at the opposite end of the 2,600-acre campus.

It is not clear if the unidentified gunman, who took his own life at Norris Hall, was the shooter at both locations.

David Jenkins, a junior at Virginia Tech, told FOX News that one of his friends was inside the Norris classroom, and played dead to avoid being shot.

While the scale of this tragedy surpasses any of the previous incidences of school violence in the U.S., experts say there are patterns in school shootings that can help administrators and students understand this type of event.

Dr. Marleen Wong, director of Crisis Counseling and Intervention Services for the Los Angeles Unified School District and director of the Trauma Services Adaptation Center for Schools and Communities in Los Angeles, Calif, said that there have been more than 600 completed school shootings since the late 1980s, with hundreds more foiled by vigilant administrators and police officers.

“With respect to this situation, a lot of the school shooters have suffered a recent loss, or feel they have suffered a failure. They didn’t have a positive connection with anyone inside their families or outside their families. That was the situation in Canada, at Dawson College. No one knew anything about him,” Wong said, referring to the shooting at Dawson College last September that left 2 dead and 19 more injured.

The U.S. Secret Service published a Safe School Initiative Report in 2002 to help school administrators identify some of the factors that contribute to students committing this sort of act.

View the Safe School Initiative Report.

The report notes that most attackers have suffered some depression, although only one-third have ever received a mental health evaluation.

Wong points out that one of the most important tasks is to recognize threats. “One of the things that we’ve learned from this, all threats should be taken seriously,” Wong said. “They need to be seen, they need to be referred to mental health services. Homicide and suicide can be two sides of the same coin. Many of the surviving school shooters have saved the last bullet for themselves but were too fearful to carry out the suicide.”

The school closed three of its academic halls on April 13, as well as one on April 2 after bomb threats, but so far there is no connection between Monday’s shooting and those threats.

Wong pointed out that it is even more difficult to evaluate a potential shooter on a college campus, because of the lack of structure. Attendance is not always taken in class, and it is easy for people to go unnoticed on sprawling campuses.

“The need for mental health services on college campuses is even greater, students have high expectations for themselves. It is a time where they should be sorting out their lives, what their strengths are, what their weaknesses are, but some people feel they are disappointing themselves or their families,” Wong said.

Counseling for Students

Dr. Spencer Eth, vice chairman of psychiatry at St. Vincent’s Hospital in New York City said there are primarily two groups of people affected by these violent events.

The first group are those directly affected, the students who were in the rooms and came directly in contact with the violence. Eth says it is these people who will be at the greatest risk for emotional symptoms.

“Then there are those not directly involved, but they are very frightened as well. You will probably want to include family members with that group,” Eth said. “They have a strong emotional connection with the event but they weren’t in the direct line of fire.”

In addition to those two major groups, Wong also identified those that knew the shooter as a group who will be strongly affected. “The other people who knew the young man, sometimes a lot of guilt emerges. One of the findings in the Safe School Initiative is that over 50 percent had been told by the perpetrator they were planning that shooting,” Wong explained.

Virginia Tech has already set up grief counseling for students, and a public gathering is scheduled on campus for Tuesday. Wong advised that this is a time for outreach, if someone is concerned for himself or herself or a friend, they should utilize that counseling.

Eth said that many people will be sad, grief stricken, depressed and anxious after violence of this magnitude. Although the grief is overwhelming following the event, Eth says only 10 to 25 percent of the people actually involved directly in the violence should develop psychiatric symptoms, such as post-traumatic stress disorder.

For those who find that the memory of this event does not fade and gets worse, they should seek professional mental counseling.

Eth also pointed out that while counseling by mental health professionals is advised for many of the people affected, it will not be right for everyone. “There are recommendations we learned about after 9/11. It’s a good time to reaffirm healthful living habits, avoid alcohol and tobacco; this is an important time to reconnect. Spirituality is helpful. Make this an opportunity to reconnect with healthy living,” Eth advised.

Eth also warned college students, “This is not the night to go out and get drunk.” And if grief counseling is not right for a particular person, Eth advises they find someone they can conveniently turn to. For some, they may be fellow students, as can already be seen by the outpouring on sites such as Facebook.com and MySpace.com.

For other students, religious groups and family may provide the best grief support. Beyond the edge of campus is an entire network of families and adults concerned for their children at Virginia Tech, and their college students in general.

Wong advises that parents and adults use this time to be in contact with the young adults who are living on campus. “It’s really important to listen to the student and what their fears may be. Too often the adult perception is in one direction, and the student direction is totally in the other,” Wong said.

“Just be available, because that may change.” For administrators, it is important that those in the school community are not re-traumatized by the event. After school violence there are often copycat threats. Wong said university administration needs to take those secretly, and track down every one who makes those threats.

Finally, Wong notes that students and the Virginia Tech community should use this time to address their concerns about any other safety issues on their campus. With questions already being raised about the university’s response time after the first shooting, questions are likely to be raised about security on college campuses.