Many Americans feel a unique connection to Las Vegas, which could cause lasting emotional reactions to the latest mass shooting regardless of where they live, experts say.
"A lot of people have a personal experience with Las Vegas," said Yu-Ru Lin, a University of Pittsburgh information sciences professor who researches human and social dynamics. "People feel like, 'That could have been me. I was just there a week ago or last month.' That personal experience makes them feel close to that area."
After the Sunday night shooting that killed 59 people and wounded hundreds more, many people expressed their anxieties on social media sites like Twitter and Facebook.
They posted feelings of fear, anger, sadness and sympathy. The hashtag #PrayForVegas quickly spread.
The reaction was familiar to Lin, who has delved into studying social media reactions from distant communities after mass tragedies over the past four years. She became fascinated with the topic after living through the 2013 Boston Marathon bombings when she was a postdoctoral research fellow at Northeastern University in Boston.
"It was a very scary experience," she said Tuesday in an interview with the Tribune-Review. "I was in a café two blocks away when people started flooding in."
For the next 24 hours, Lin was glued to social media as the city remained locked down during the search for the bombers.
"First you fear, then you feel shock, especially when you don't know what happened," she said. "You are eager to find out information from anywhere. And you want to send out feelings of comfort to the city which is suffering."
Lin and her research colleague, Drew Margolin, now an assistant professor of communication at Cornell University in New York, embarked on an in-depth study in which they analyzed 180 million tweets over a month after the marathon bombings. They studied how Twitter users from different cities across the country and world expressed fear, sympathy and solidarity.
"We showed that people who had visited Boston recently before the bombings were more likely to express fear and also to associate with tweeting the #BostonStrong hashtag," Margolin said.
In a second study after terrorist attacks in Paris on Nov. 13, 2015, Lin and Margolin analyzed 18 million tweets from 15,509 users located in Paris. They they found those in closest proximity to the attacks experienced the most distress. Those who remained near the attack site in the following days experienced fear and anxiety for longer periods.
"The closer you are to the site, the longer the distress lasts," Margolin said. "I was in New York during 9/11 and for days you could smell the burning. That smell reminded you all the time about what had happened; you could feel it."
The reaction to the Las Vegas shootings could be different because it's one of the nation's top tourist destinations with more than 40 million visitors a year.
"I have stayed in Mandalay Bay," Margolin said of the hotel where the gunman opened fire. "I've been to Las Vegas three times and it hit me right away that I have stayed there. It definitely makes it more creepy.
"That city is such a unique entity, the fact that so many people have been there will expand the feeling of connection."
Generally, Margolin and Lin found that the outpouring of emotion on social media from individuals after mass tragedies lasted anywhere from four days to a week.
Margolin did not discount the premise that Americans have become accustomed to these incidents.
"There is that belief among some that this is not a novelty anymore," he said. "People know terrorism happens and it can be really devastating and government is supposed to address it."
That makes it hard to predict how long it might take for U.S. residents to collectively move on from the tragedy in Las Vegas, he said.
"I am already collecting data and me and my group are preparing to study this," Lin said. "This is an opportunity to for us to try and make sense about what is happening around us to us."