April 16, 2013— -- For Carlos and Melida Arredondo, the explosions they watched firsthand from the VIP stands at the Boston Marathon reverberated like terrible flashbacks. They lost two sons violently: One was killed at age 20 by sniper fire in Najaf, Iraq, in 2004 and the other took his own life.
"I am still very shaken," said Carlos, who is Red Cross trained and stayed on to help. "I am covered with blood and still at the scene where the tragedy happened. I jumped the fence after the first explosions and all I saw was a puddle of blood and people with lost limbs. I saw adults, much younger than myself -- ladies, men, pretty much everyone was knocked out."
FULL COVERAGE of the Boston Marathon bombings
The couple, who live in Boston, watched as more than 130 runners and bystanders were injured at the finish line.
READ: 8-Year-Old Died at Boston Marathon Waiting to Greet Father
They were waiting for the last of the National Guard runners, representing Run for the Fallen Maine, an organization established to honor Marines who have been killed since the terror attacks of Sept. 11, 2001. One of the National Guard runners was in the marathon in honor of their son. They were also supporting a suicide awareness group, Samaritans, which also had runners in the race.
SEE: photos of the chaos at the finish line
Lance Cpl. Alexander Arredondo, whose mother was from Bangor, Maine, served two tours in Iraq with the Marines. The news of his death on Aug. 25, 2004, devastated his younger brother, Brian, who hung himself in 2011 at the age of 24.
"They were very close -- Irish twins," said their stepmother Melida Arredondo.
"The only document we found with him [Brian] was the casualty report of how his brother died," said Carlos Arredondo, who immigrated to the United States from Costa Rica and became a U.S. citizen with the help of Sen. Edward Kennedy. "He died of grief."
WATCH: Marathon witness Rachel Sibley's account
Monday's carnage reminded Arredondo, a Gold Star Parent who has been active in veterans' groups, of an Iraq war zone.
"It was like an IED [improvised explosive device]," he said. "It broke everybody's legs. Two ladies at my left side were knocked unconscious. They lost their legs. I was putting pieces of clothing on their legs to stop the bleeding and called for assistance. Someone came and we helped get them in wheelchairs."
Both husband and wife had been sitting in the bleachers. After the first explosion, Arredondo jumped the fence.
"My first reaction was to run toward the people," he said. "There was so much commotion and a lot of people running away. I was one of the first to help people and God protected me. It was horrific."
"Carlos was a real hero," said John Mixon, 60, of Ogunquit, Maine. "He jumped right over the fence even before there were police and tried to help people."
At first, his wife Melida, a public health administrator, stayed in the stands.
"I was in the bleachers at the finish line, looking right at the explosion," she said. "We were watching and waving at the runners as they were coming in. My husband was at the finish line talking to the Guardsmen about the one who had Alexander's name [on his shirt]. One bomb went off -- we all hit the decks, but we were calm at that point."
"The second bomb went off and everyone in the VIP bleachers went crazy," Melida Arredondo said. "I was dizzy trying to get off the top deck."
She finally found her way to the bottom and first responders were encouraging people to get off the street and "go into buildings."
"I know my husband, and he would go right in," she said. "They opened all the barricades that were keeping the public away. There were shards and people cut and injured."
She sought shelter on the other side of the street by the Boston Public Library, but couldn't find her husband.
"I couldn't even get a text to him," she said. Eyewitnesses reported that cell phones were blocked by the deluge of calls after the explosions. "Then I saw him, covered in blood."
Her husband was "rinsed off and sent on his happy way," according to Melida Arredondo. "I took the train home. I was nervous and didn't know where to go at first. It was a bit confusing."
Most the National Guard runners had made it to the finish line before the explosions -- all but one, and the couple said they had no idea what his fate was.
When Melida Arredondo finally got a chance to clear her head at home, she said, "I immediately went back to my stepson who we lost in Iraq."
Melida Arredondo said she has been concerned about the "all the children" who were injured in the marathon explosions.
And she thought of her stepson Brian, who couldn't cope with life without Alexander.
"He was never quite the same after his brother's death," she said. Just before the older boy's death, the brothers were making plans together to go to California.
"We are running on adrenaline right now and unfortunately we have a lot of experience," she said, cutting off her sentence, but meaning, unmistakably -- trauma.