Among the eight people who were killed in the New York City terrorist attack on Tuesday are five men from Argentina. They were in the city celebrating the 30th anniversary of their high school graduation when their lives were viciously cut short by a 29-year-old ISIS-radicalized immigrant from Uzbekistan.

Another member of the group is hospitalized in critical condition.

Wearing shirts emblazoned with the word “LIBRE,” the Spanish word for “free,” the group of eight men happily posed for a photo as they set off on the trip. They were raised in the Argentinian city of Rosario, which has declared three days of mourning as a tribute to the dead, according to a CBS News report.

One of the other people among those killed in Tuesday’s attack was from Belgium.

The tourists who were killed were run over by the truck moments before it rammed into a school bus carrying adults and special needs children. One man who captured video of the mangled bus told reporters that what he witnessed was “extraordinary and horrific.” Four people were in the school bus.

“I just realized that that guy in the street had just basically plowed, T-boned a bus full of kids,” witness Sebastian Sobczak said. He recalled thinking at the time, “I have to chronicle this, I have to see who is on that bus, I have to get the word out to the parents.”

The passenger side of the bus was caved in. Two adults and two students on the bus were hurt.

“The window was knocked out, it was apparent that one of the kids flew across that and broke the window with his head – it was bleeding,” Sobczak remembered. “And then, I saw a little girl trapped in the wheel well of that bus, and some, really, pretty horrific sights.”

Sobczak said the bus driver was a hero, despite his injuries. “The bus driver, I really feel for him,” he said, adding, “You could tell he was hurt. He was selfless in trying to get those kids out of the bus. He was in shock.”

A father of three himself, Sobczak said he wanted to make sure the children were safe. “The unknown is the terror that all parents have. I’ve never seen anything like that, and so it’s all surreal. I’m not sure how I’m gonna sleep tonight,” he said.