Katie Mason spent her Friday afternoon exploring the tourist attractions of Paris, taking in a panoramic view of the city after walking to the top of the Eiffel Tower.

But by nightfall, a magical afternoon quickly gave way to what she says is a “senseless tragedy.”

Mason, a junior hospitality and tourism major at the University of Massachusetts, was in Paris Friday when a series of coordinated attacks throughout the city left 129 people dead and more than 300 injured, some critically. The violence set off a European manhunt for potential suspects behind the assaults and prompted French President Francois Hollande to pledge vengeance against the Islamic State, which has claimed responsibility for the attacks.

Mason, who is studying abroad in Florence, Italy this semester, visited Paris last weekend with friends and was staying in an apartment just one mile away from the Bataclan concert hall, where four gunmen opened fire and killed 89 people in the audience of a concert.

“I feel so fortunate that we weren’t in the wrong place at the wrong time Friday,” Mason told the Daily Collegian. “My heart breaks for all of those that were not as lucky as we were.”

UMass Director of Education Abroad, Kalpen Trivedi, said in an email to the Collegian Tuesday that all University students studying abroad in Paris and its surrounding areas of France are safe and accounted for. At least one American student, Nohemi Gonzalez, 23, of California State University, Long Beach, died in the attacks last Friday.

Mason said she and two other friends, who are also UMass students, arrived in Paris Thursday night and planned to meet others that weekend. She said her group of friends were waiting to meet another friend, who was en route to Mason via train Friday evening at the Les Halles metro station. Mason began to receive text messages from friends in the United States concerned about her safety as she waited at the station.

She said they didn’t think much of what they believed to be some type of shooting in central Paris, but when her friend arrived at the train station, Mason realized something was wrong.

“(My friend) said that when she was on the metro, it skipped two stops and people were panicking,” Mason said.  “She knew things were bad.”

The women quickly returned to their apartment in the city’s second arrondisement neighborhood, which was five minutes away. Mason then learned about the severity of the violence as messages from friends and family rolled in.

“We were safely back at the apartment when we realized what was happening,” she said.

“Once I read frantic messages from my worried parents, I immediately started crying. I knew I was safe, but the feelings of sadness, fear and uncertainty hit me all at once.”

Three teams of terrorists carried out coordinated attacks involving gunfire and triggered explosives at multiple sites throughout the city, including the concert hall, a soccer stadium and roadside cafes. Seven of the eight terrorists died in the attacks, per French police, while an eighth, Abdeslam Salah, remains at large.

In response, Hollande has said France is “at war” with the Islamic State and has called for efforts to ramp up military actions. French military launched airstrikes targeting Islamic State sites in Syria Sunday night, and Hollande said he’d allow the government to carry out more police raids in the near future.

French and Belgium officials have tentatively identified a suspect behind the attack, 27-year-old Abdelhamid Abaaoud of Belgium.

Mason said she felt “at risk” as she returned to her apartment Friday, but didn’t witness any violence firsthand and didn’t venture out into the city in the aftermath of the attacks on Saturday or Sunday. She left Paris on a flight to Bologna, Italy Sunday night.

Following the violence, Mason said she felt a mixture of emotions, including anger, fear and heartbreak.  However, she said she hopes to return to Paris one day amid “happier” times.

“I will never understand how people can be so heartless to take the lives of innocent people,” she said. “It’s just not fair, and it makes me sick to my stomach.”

Mark Chiarelli can be reached at [email protected] and followed on Twitter @Mark_Chiarelli.