(2/26/2018) -- On this day 25 years ago, an ugly new phase of terrorism began in the western world.

It was Feb. 26, 1993 when radical Islamic terrorists first attacked the World Trade Center by detonating a 1,200-pound bomb that was placed in a rented vehicle that had been driven into the basement parking level in the north tower.

Once the 20-foot fuse was lit and the suspects made a run for it, a catastrophic explosion killed six people, including a pregnant woman, and injured over 1,000 people. About 50,000 people were evacuated from both towers.

A ceremony held on Monday at the World Trade Center site in Lower Manhattan honored those who lost their lives and were impacted by the attack. The event would change the way America viewed its safety, vulnerability, and the way we now train, prepare for, and prevent acts of terror.

A moment of silence was observed at exactly 12:18 p.m. EST on the 9/11 Memorial Plaza, marking the exact time the bomb went off.

The victims ranged in age and in job titles and all were in the wrong place at the wrong time. John DiGiovanni, was 45 years old, and was working as a dental supply salesman visiting the World Trade Center that day. 

Robert Kirkpatrick, age 61, was senior structural maintenance supervisor for the World Trade Center for the Port Authority of New York and New Jersey. Other Port Authority workers include Stephen A. Knapp, 47, and the chief mechanical supervisor for the World Trade Center. 

Other WTC employees included 57-year-old William Macko, assistant chief mechanical supervisor for the World Trade Center, and 35-year-old Monica Rodriquez Smith, a mechanical unit secretary for World Trade Center Maintenance. She was pregnant and was scheduled to take her maternity leave the next day. Wilfredo Mercado, 37, who worked in purchasing for Windows on the World International Hilton Company, also died that day.

‘The wound is always there, I would say, the scar tissue just gets, you know stronger, but it’s certainly on any anniversary, certainly on a big one like this I think about it a lot,” said Macko’s son, Michael, who spoke to reporters after the ceremony. “I think about my father and that day and, you know, all that he's missed."

Stephen Knapp, whose father was killed in the explosion, said he still struggles with his emotions.

"I've gone through a whole host of emotions in the 25 years the shock and sadness when it first started, then going through the anger that somebody could actually do this,” he said. “As I've grown older I've gone through that range of emotions and the one thing that sticks with me is the sadness, that there are people out there that continually do this. And '93 was just the start of it in this country and seems like building up and getting more and more escalated."

Rick Cotton, the executive director of the Port Authority of New York and New Jersey, spoke at Monday’s ceremony, telling the crowd: "The best way we can pay tribute for those who were lost in 1993, is to make sure that no other family has to live with pain and suffering these families have lived with."

The 1993 bombing has long been seen as a foreshadowing of the terror attacks that have hit the U.S. since that tragic day, and while six men were captured, convicted and are serving life sentences, the F.B.I. is still after one man, Rahman Yasin, who is considered the seventh suspect in the case.

Federal prosecutors say Yasin is part of a group of Muslim extremists who sought to punish the U.S. for its Middle East policies, which was the motive for the attack. Ramzi Yousef, the ringleader of the attack, is serving a life sentence for the bombing, and is also the nephew of the infamous Khalid Sheikh Mohammed, who later claimed to be the mastermind of the 9/11 attacks.

Investigators tied all seven suspects in the case to an Egyptian fundamentalist cleric Sheik Omar Abdel Rahman, also known as the "Blind Sheik," who was convicted of masterminding several attacks against the U.S.

Rahman died in prison last year. The others who were convicted in 1994 were sentenced to prison terms of 240 years each.