The city of light grew dark Friday night as eight Islamic State terrorists unleashed a terror that many French residents haven't experienced in the city in decades during the deadliest attack in Paris' history since World War II.

Six locations throughout the city were targeted by the terrorists, leaving 129 people dead and 352 injured when all was said and done.The weekend was tense as reports of additional ISIS threats surfaced and French President Francois Hollande vowed "merciless war on the group before deploying airstrikes on the group's headquarters in Syria.Madison and Darby McCall, daughters of Times News Sports Editor Emmett McCall, who are both currently in Spain as part of study abroad programs for their respective colleges, said that the tragedy was even felt in Spain."I was visiting my sister Madison in Barcelona this weekend and there was a very noticeable difference in airport security between Friday afternoon when I flew in and Sunday night when I flew out," Darby said."On Sunday, after we went through the normal security checkpoint, there were police and military personnel in vests and carrying machine guns that were approaching passengers and asking questions."That wasn't the case on Friday. There also seemed to be a lot more people getting pulled out for searches than normal on Sunday."The gate I was at in the airport happened to be right next to the gate for a flight that was flying into Paris," Darby said. "The people at the gate actually had a second security check by Spanish police before they boarded their flight."Darby said that the program moderators called the students in her program on Saturday to confirm everyone was safe and urged them to keep a low profile in the following days.Madison echoed her sister's thoughts about the change in the atmosphere following the attacks."I've been in Barcelona since the end of August and I definitely noticed a difference this weekend," she said. "When we went out on Saturday, we saw police with fluorescent vests and machine guns patrolling the major tourists areas. I never noticed that when I was in those areas previously."My friend Nick (Wachter), who I went to high school with, is studying abroad in Denmark this semester, and he was in Paris when the attacks happened. He was staying just a couple of miles away from where everything happened. I knew he was going to be there so I was relieved to see his Facebook post that he was safe."Reporter Judy Dolgos-Kramer's daughter Emily was scared for her friend Rebecca Walker, who lives in Lichfield, United Kingdom, but was in Paris on Friday. The two met when Emily had traveled to Madrid.Emily sent a message with Rebecca's accounts."I was in a restaurant having dinner near Les Halles," Rebecca reported. "There was a TV in there and at about 10:20 they turned it over to the news. People were obviously very worried but there wasn't any sort of mass panic really. As more news started coming in we noticed less and less people on the street."I have had to stay with a friend who luckily lives fairly close because I couldn't get a taxi and didn't want to take the metro. There were obviously a lot of sirens though and many people looking very anxious."The streets are pretty empty and a lot of places are closed," Rebecca continued. "People are still being advised to stay at home if possible, but there's not much else to report really."The horror that covered Europe has also been felt in the United States, leaving travelers to deal with tighter security as echoes of 9/11 crept through the country.Time Square, sports stadiums, Mall of America and airports took precautionary measures over the weekend to ensure the safety of the people they serve.New York Police Department deployed its "Critical Response Command" - officers equipped with heavy weapons and other tactical equipment - to important locations including transportation hubs and the Broadway theater district. Officers with radiation detectors and bomb-detecting equipment were sent to subway stations and were randomly conducting bag checks.In Washington, D.C., additional law enforcement officers were deployed to French-owned sites and other high-profile locations out of "an abundance of caution."In Boston, the Massachusetts State Police said there was "a comprehensive and multilayered security package" in place at Logan International Airport and enhanced patrols near the State House.The U.S. flag was also lowered to half-staff at the White House, federal buildings across the country and American military and diplomatic stations around the world as a mark of respect for victims of the Paris attacks.President Barack Obama ordered the gesture of solidarity with France by proclamation Sunday.The flags will be flown at half-staff until sunset Thursday.Times News staff Emmett McCall and Judy Dolgos-Kramer and The Associated Press contributed to this story.