Ross Zimmerman was frantically looking for his 30-year-old son Gabe in the emergency room on Saturday in Tucson when a dreadful thought occurred to him.
"Nobody could find him, and that's when the horrible realization dawned on us that they couldn't find him because he wasn't in any emergency room," Zimmerman told ABC's Christiane Amanpour. "He had died at the scene -- and half of my future is gone."
The younger Zimmerman was the director of community outreach for Rep. Gabrielle Giffords, D-Ariz., who was shot in the head that tragic morning, the target of an assassination attempt allegedly carried out by Jared Lee Loughner, 22.
The shooting -- in which at least six people were killed and 14 were wounded -- left Congressional staffers shaken but united, many of them told ABC News. Gabe Zimmerman was one of their number.
"There's a sense of unity right now and a sense of camaraderie among staffers that work for people," one staffer said. "I think that everybody can relate to the young man who was slain in the incident because a lot of people who work in members' offices do exactly the type of job that he was performing that day -- reaching out to constituents, organizing an event like that, working with local elected officials to make sure they're aware of it, and making sure that it runs smoothly for your boss."
"What he was carrying out is a core duty of anybody that works for a member -- and he very much fit the profile of an average staffer that works for a member, so I think that everybody can relate to that person and everybody's thinking of him and his family and his fiancee that lost him. It's a helpless feeling because a lot of people would like to do something to help or contribute."
On Monday hundreds of staffers joined with a handful of members of Congress in a moment of silence on the steps of the Capitol. Many lawmakers said that Saturday's shooting will not make them change their ways when they are back in their home districts.
"I will not be paralyzed by fear," Rep. Hank Johnson, D-Ga., said after the moment of silence. "I will not look at my citizens and automatically think that I am in danger."
Tragedy in Tucson: Capitol Hill Carries On
Said Rep. Fred Upton, R-Mich., "I am not concerned, and if I were I don't see how I could be a member of the House of Representatives. Our mandate is to get as close to the people as possible."
"In reality, you would really change the way that we operate if you impose such a new set of restrictions, and for the most part, I think most of us would balk at it," Rep. Eleanor Holmes Norton, D-D.C., told reporters.
However, others such as Utah Republican Jason Chaffetz have decided to carry a gun when they are back in their home districts.
So the next time a Congressional staffer is standing at a public event with their boss, will they feel differently today than they did only a week ago?
"I think that this incident will obviously be on the minds of people for a long, long time, but it cannot and will not disrupt the way that members of Congress and their staff go about performing their jobs," a Congressional staffer said.
"I don't think you'll see members all of a sudden clear their schedules of public events that bring them in contact with their constituents. I think people will be mindful of it in that they'll have heightened situational awareness at events that they do, but I don't think it'll stop them from scheduling that event and executing that event - that would be bad for Congress and bad for the country if that happened."
One former Hill staffer told ABC News that there have only been a handful of incidents in her career when she ever feared for her safety.
"There have certainly been individual instances where I've been nervous about my safety, but I've generally never felt any less safe at an event for my boss than I have on a plane or crossing the street," the staffer said.
"We sometimes get so lost in the work we're doing that we don't realize the potential consequences it may bring."
Once, the staffer said, her former boss was named in a trailer for a movie encouraging gang members to kill people viewed as threats, and her cell phone number was obtained by the movie's creator.
Tucson Shootings and Capitol Hill Staffers
"That was truly terrifying for me," the staffer said. "At the same time, though, I saw it as a message that we were making progress and doing something right, and it was more important than ever not to back down in fear."
"There are eye-opening experiences when you realize that the work you do for Congress may put you at risk, but aside from a few scattered and extreme cases, I've never been concerned about my safety," she said.
ABC News' John Parkinson contributed to this report.