Three people Krystle Campbell (29), Chinese exchange student Lu Lingzi (23) and perhaps the most heartbreaking of all, Martin Richard (eight) lost their lives; hundreds were injured and thousands were scarred.
Within hours of the story breaking in Ireland, I was on flight to Boston to cover the aftermath .
In the time it took for me to fly from Dublin to Logan Airport, the city was transformed. No suspects had been identified; no terrorist organisations had taken credit for the act; the number of casualties were still unclear and security was at an all time high.
Immediately after the bombings, the FBI said they knew the bombs were made from pressure cookers packed with explosives but had not yet detected any suspects or motives.
On my arrival, I visited little Martin Richard's nearby primary school, I joined the crowds at the Cathedral of The Holy Cross while US President Barack Obama attended a mass in memory of the victims and I was one of millions who had to go about 'business as usual; to the backdrop of sirens and seeing machine gun wielding soldiers roaming the streets.
The dramatic scenes after the Boston Marathon Bombings on April 15, 2013
I visited the Boston Medical Center, one of the many hospitals caring for victims. I knocked on doors, I visited memorial sites, I attended services and listened to anyone who would speak to me. I joined the masses at Joe Moakley Federal Courthouse in where a suspect was believed to have been taken into custody (this later proved to be false, one of the many incorrect reports throughout the week). I stayed even after police had warned another bomb threat was called in.
I sat in horror as I watched Lu Lingzi's father tearfully pay tribute to his daughter, I read in disbelief as Krystle Campbell's family had originally been told she survived and I choked back tears seeing Martin Richard's father struggle to comprehend the loss of his eight-year-old, while his wife Denise and daughter Jane were treated for their own injuries incurred at the finishing line.
Martin Richard (eight) died in the bombing
On April 18th, I, like millions of others in Boston went to bed (later than normal to catch the local news in case I had missed anything) and just before committing to a night of sleep, I saw the breaking news that campus police officer Sean Collier had been shot and killed at the Massachusetts Institute of Technology campus.
Over the next 36 hours, sleep was no longer a luxury I could afford in fear of missing a moment to report, joining countless others - many of whom were too fearful to rest their wary heads.
Following Mr Collier's death, two local brothers Dzhokhar and Tamerlan Tsarnaev had been identified as the suspects responsible for the marathon attack. And so began an early morning gun battle with police authorities who tracked them to Watertown, where they were in hiding.
The city goes into lockdown. No one was allowed in or out; the subway was closed off; buses were cancelled; taxis were few and far between. The streets of Boston city centre are deserted, with only myself and a few other foolishly minded folks walking the streets.
During the shootout, older brother Tamerlan (who was previously flagged to the FBI for his radical Islam beliefs and he is investigation with potential terrorist links in 2011) dies. His younger brother, who had until just a few days previous, attended college at the University of Massachusetts, Dartmouth is on the run - wounded and bleeding.
Dzhokhar Tsarnaev is awaiting trial
After endless hours of exhaustive searching, the lockdown is lifted. Within an hour, authorities traced the teenager to an unsuspecting resident's backyard where he was hiding underneath the tarp of their boat. Directly next door to an Irish family who were evacuated when the search began.
He was taken into custody, taken to hospital for treatment and charged in his hospital room. He is currently awaiting trial where prosecutors are pushing for the death penalty.
And then it was over. Life was to resume as normal.
In times of distress, many just want answers. They want to see the culprit locked away safely from society and they want to put the tragedy behind them. The people of Boston were denied that during an unbearably tense three days.
In the interim, a teenager who was reported missing by his parents had been wrongly identified as Suspect Number One; police radar moved faster than we could keep up and there was more fiction than fact when it came to the majority of reportage.
It's exactly one year on in Boston and the city has flourished once again. It's back to its beautiful best.
Gillian Reny began walking again in August and she is finishing off her freshman year at the University of Pennsylvania; J.P and Paul Norden both lost a leg and are slowly rebuilding their lives.