PHILADELPHIA - Glenda Laudisio had left the offices of ZigZag Net Inc. on Feb. 12, 2007, when Vincent Dortch showed up for an evening meeting with Ms. Laudisio's boss and three business partners in the small Philadelphia advertising company's conference room.
After exchanging pleasantries, Mr. Dortch, an investor, pulled out a gun and killed three of the four people in the room before killing himself. The fourth, wounded, survived.
This month Yvonne Hiller, a longtime employee at Kraft Foods' Philadelphia plant, allegedly shot and killed two co-workers and wounded two others while a hundred terrified employees tried to avoid harm.
The day after the shootings at ZigZag, it was up to Ms. Laudisio to pick up the pieces. She soon closed the business, and she never went back into the conference room. "We had to move on," said Ms. Laudisio, who heads Eight Eleven Inc., a Camden, N.J., advertising agency she opened.
Although she was skeptical at the time, it turned out that a group session with her fellow employees and a counselor shortly after the slayings helped.
"At that time, I wasn't sure about rehashing and digging it up, but I think it did give us a chance to get it out and deal with it," she said.
Some people spoke; others did not. But even those who remained silent, she said, "got to be with people who were facing the same issues."
Kraft has said it would offer counseling to its employees.
Such counseling is critical to their well-being, said Jan Paul of Seattle, co-chairman of the workplace disaster-response committee of the Employee Assistance Professionals Association, an organization of workplace counselors.
Now in private practice, Ms. Paul estimates she debriefs employees in two workplace homicides a year in an annual caseload of four dozen workplace deaths - suicides, sudden deaths, and fatal accidents.
Initially, she said, employees crave information, and it is up to management to provide as much as it can and as frequently as it can, given boundaries imposed by police investigations.
"You need to normalize responses," she said. Tell employees that certain reactions - numbness, depression, sleep irregularity, fear, flashbacks - are normal responses to trauma. People feel like they are going crazy."
It may be necessary to close the work site temporarily, but, she said, "being at work helps normalize things. That is where the other people are who are going through the same experience."
One problem is dealing with the site of the murders. In the ZigZag case, it was a conference room. At Kraft, it was a break room. "People are going to have a fear of going back into that room," Ms. Paul said.
Sometimes rooms are changed, painted, or assigned a new purpose. "Some people might want to smudge it," she said, referring to an American Indian purification ceremony that uses smoke. "Or they might want to have something with food in there, some way of purging what went on in the room."
According to Washington state's employee assistance protocol for workplace trauma, workers often experience physical symptoms, such as stomach pains, without a medical explanation or may feel out of control or hypervigilant and easily startled. They may avoid or refuse to return to work or to use equipment associated with the trauma, or may have unexplained absences or increased use of sick and vacation time.