SOUTH PORTLAND – Matt Cox is not a runner, but he’s spent months training to take part in Monday’s Boston Marathon after witnessing the horrific aftermath of last year’s race, when two homemade bombs were detonated at the finish line.

The blasts killed three people, including 8-year-old Martin Richard, and severely injured scores of others, many of whom lost limbs in the bombings, which were a mere 12 seconds apart.

Cox was at the marathon supporting his wife’s friend who had just finished running. Cox and his wife were watching the race across the street from the Forum restaurant on Boylston Street and had just left the area when the first bomb exploded.

“The explosion actually sounded like a large metallic bang, the kind of noise that might be made when the tailgate of a dump truck hits the ground,” Cox recalled.

He remembers getting a “sinking feeling,” and then he heard the second explosion.

Cox, his wife and their friends could not see what was happening, but he said shortly after the second bomb went off he saw an “ambulance go flying by,” followed moments later by police officers on foot who were running and carrying backboards.

Cox said that sight stopped him in his tracks and he called his mother and asked her to turn on the news. His mother told Cox that two bombs had gone off and that’s when Cox, who is a firefighter/paramedic in South Portland, made an important decision.

Instead of running away from the scene, he turned back to see what he could do to help. When he got to the main medical tent, where only moments before runners were being treated for dehydration and fatigue, he showed his paramedic badge to a race official and asked to be put to work.

Cox said only about 10 minutes had elapsed between the time he heard the first explosion and his arrival at the medical tent, which had been quickly turned into what he described as “a mass casualty triage center.”

“I’ve never seen anything like it,” he recalled. “It was the worst thing I’ve ever seen. As a paramedic, I am used to blood and gore, but this was a whole different thing.”

Cox said even though he arrived a short time after the bombs exploded, Boston first responders had already sent many of the most seriously wounded to area hospitals. Even so, there was still a lot to be done.

Cox said he’s not a hero and does not want to be compared with those who jumped immediately into the fray to save lives.

“I didn’t save anyone,” he said. “I just helped where I could, checking tourniquets and IVs. There were so many people with injuries to treat, but those injuries were not necessarily life threatening.”

In the end, Cox ended up staying on scene for about three hours, and said the worst part was not knowing if he and the others in the medical tent were safe from another attack.

Eventually he reunited with his wife and friends and then called his father, who lives near Boston, to come pick them up. Originally the group was intending to stay at a hotel near Fenway Park, but Cox said his only goal after leaving the medical tent was “to get out of the city.”

Cox said in the weeks following the bombings he went through all seven stages of grief, starting with shock and ending in “a funk” that was only partly alleviated when the bombers were identified and one of them was caught alive.

Authorities have said that Dzhokhar Tsarnaev and his older brother, Tamerlan, were the bombers. In addition to those killed in the bombings, the brothers are also accused of killing a campus police officer at the Massachusetts Institute of Technology.

Tamerlan Tsarnaev was killed in a confrontation with police and Dzhokhar Tsarnaev was arrested after trying to hide out in a boat located in the back yard of a home in Watertown. Dzhokhar Tsarnaev is now facing 30 federal charges and is expected to go to trial this fall.

Cox said the reason he’s running in this year’s marathon, which is always held on Patriots Day – a holiday in Massachusetts and Maine – is because he wants to be part of the effort to “reclaim the event and make it a positive experience” once again.

Cox, who lives in Wells with his wife and two children, ages 6 and 3, has run in one marathon before. That was in 2009 when he was living in Oregon. Although he supplements his income by working as a personal trainer, Cox plans to hang up his running shoes following next week’s event.

Cox is part of Team MR8, a group of runners raising money for the Martin W. Richard Charitable Foundation, which was founded by the family of the young boy killed in the bombings. Cox’s goal is to raise $5,000, and so far he’s received about $1,700 from supporters.

Cox said if he doesn’t reach his fundraising goal, that’s all right because “any amount raised for this cause is worthwhile. All I’m trying to do is help out a worthy charity.”

While he doesn’t expect anything to happen at this year’s marathon, Cox said he’s keeping his wife and children away from the finish line and admits to having “some anxiety.”

“Unfortunately this is the world we live in now,” Cox said about his immediate thought that it was in fact a bomb when he heard the first explosion at last year’s race. “But that doesn’t mean we shouldn’t go about our normal business.”

A CLOSER LOOK

Matt Cox, a South Portland firefighter/paramedic, is taking part in this year’s Boston Marathon. He is dedicating his run to the Martin W. Richard Charitable Foundation, which was founded by the family of Richard, the 8-year-old boy killed in the marathon bombings last April. See www.firstgiving.com/fundraiser/matt-cox/friends for more information, including how to donate.

With Bug Light in the background, South Portland firefighter/EMT Matt Cox is training to run in this Monday’s Boston Marathon. Cox, who was near the finish line at last year’s race when the bombings occurred, spent hours aiding victims. He plans to run the iconic 26.2-mile race to raise money for a charity set up in honor of the 8-year-old boy killed in the attack. Matt Cox