She could feel excruciating surges of pain throbbing in her back and legs as she passed the 25-mile mark of the Boston Marathon. The race was taking its toll on Juli Windsor’s 3-foot-9-inch frame.

Instead of backing off, the 26-year-old Cumming native smothered the discomfort and kept her legs in rapid motion. By maintaining a 9- to 10-minute per mile pace, she was approaching her personal best time and poised to become the first person with a diagnosed form of dwarfism to ever cross the finish line.

Just as she kicked it into a higher gear for the last half mile, authorities blocked the road. The race had been canceled. Shock replaced confusion as Windsor heard the news. There had been two explosions minutes before at the finish line, the place her family gathered to wait for her arrival.

“I fully expected to cry out of joy once I crossed the finish line,” Windsor said, “but I never anticipated to cry out of complete fear prior.”

In the flash of a senseless act of violence, Windsor’s dream was stopped in its tracks. It was a dream that dates to her sophomore year of high school. On the top of her list of life goals that year, Windsor had written “Run the Boston Marathon.”

Despite her diminutive stature, Windsor’s unrelenting resolve and zest for life have always been apparent to those who know her.

“It took me until my teenage years to realize that other people consider Juli to be handicapped,” said her younger brother, Joseph Erickson. “The term simply doesn’t apply to her in my mind. … She never lets someone’s criticism or doubt obscure her aim to accomplish a goal. Rather, she gracefully dismisses a harsh word and continues with persistence.”

After joining her middle school cross country team, she was bitten by the running bug. Windsor competed alongside average-size competitors through high school and into her first year of college. She ran well into adulthood, taking twice as many steps as the typical runner, pushing herself and entering more and more road races. The Boston Marathon still loomed as the pinnacle.

“When you put yourself in the runner’s world, you learn about the Boston Marathon,” she said. “It’s like this glorified dream of every runner. It’s got this prestige, this beauty about it.”

In 2010 Windsor ran her first marathon in less than five hours. In 2012, in the throes of pneumonia, she qualified for Boston’s mobility-impaired division by finishing the BayState Marathon in Lowell, Mass., just shy of six hours.

Then came preparations to check off No. 1 on that childhood list. In January, she started a 16-week training program in icy Minneapolis, juggling running with her clinical rotation for a physician’s assistant degree. She focused on speed work Mondays and Wednesdays and ran between 10 and 13 miles on two other days. She saved longer runs for Saturdays.

“The marathon isn’t the hard part,” Windsor said. “The race day is an exciting thing. You’ve worked hard up to that point, and you’re ready. It’s the training that’s the tough part. … There was so much time committed to training for this one day.”

Monday, her husband, Blake, her mother, Anita Erickson, and mother-in-law, Sue Windsor, gathered at Boston’s finish line as her cheering section.

“I was praying before the race,” Erickson recalled. “When Juli was a child, my husband and I would always tell her she had a purpose in her life. I thought, ‘God, this must be one of your purposes for her.’ So there was that exhilarating sense of adventure.”

Windsor said: “Sometimes you make these dreams that are high and lofty, and you don’t think they’re going to manifest, and here I was on the bus [to the starting line] with my number patched to my shirt and ready to go run the race. It was a very surreal moment.”

The race began, and every photo capturing Windsor in midstride showed a beaming smile stretched across her face. The Boston Globe plastered her picture on the cover just days earlier, making her a race celebrity of sorts. Onlookers cheered her on and gave her high-fives along the way.

As Windsor entered mile eight, the pain began. Because her back curves inward, she typically feels back pain beginning at mile 12. This time it came early. Friends running with her gave her ibuprofen and put medicine on her back.

There were periods during the race that were so painful she considered throwing in the towel. Yet, she trudged ahead toward the promise that her aches would soon be washed away with accomplishment.

She was at an emotional high at the 25.7 mile mark, set to finish 15 minutes behind her original goal of 4 hours and 15 minutes but thrilled with her potential time. Then when the authorities broke the news, one of the greatest moments of her life was threatening to become one of the worst.

“So an adrenaline rush of excitement turns into an adrenaline rush of fear,” she said. “I didn’t even know what to do with myself.”

Having recently passed her friend John Young, the only other little person running the race, Windsor backtracked to find him. Both had family at the finish. With the phone lines down, there was no way of knowing if their loved ones were safe.

“All I could do at that moment was pray,” Windsor said, “just realizing that I’m not in control, and regardless of what happens that God has had his hand over my life, and I can continue trusting in him regardless of what happens. That’s all I could hold onto.”

Before the race, Windsor called her husband to remind him that she typically runs on the right side of the road, which may have saved their lives. The trio of supporters were enjoying the sun, but they moved across the street to have a better view of Windsor’s arrival. Had they remained in the same spot, they would’ve been directly in front of the second explosion. And had Windsor met her original goal, she could have crossed the finish line in the heat of the disaster.

As bombs went off, Erickson was separated in the chaos from her son-in-law and his mother.

“There was this huge psychological thing going on as the bombs went off,” Erickson said. “Once you hear two explosions, you fear for more. … Not only are you dealing with fear, but you’re wondering if you’re going to actually die. So you’re trying to deal with reality and emotions in seconds.”

Erickson was accidentally pushed to the ground and suffered a shoulder injury and a black eye. She and others were corralled into a nearby store. As she sat in pain wondering about her daughter’s safety, Erickson said a woman she didn’t know comforted her and remained by her side throughout her trip to the hospital.

After about two hours, Erickson was released, and Windsor and her family came together for an emotion-filled reunion. Erickson said they spent the next 24 hours processing what had happened, wading through the tears, the tragedy and loss as best they could.

It was then Erickson said she found yet another reason to be inspired by her daughter.

“Juli’s doing better than I am,” she said. “I feel like her training program and her whole life of being disciplined and having a goal has trained her spirit. … As a parent, I wonder if her message and her spirit might have more of an effect [on others] now than if she had finished the race.”

Though she technically didn’t finish, race officials gave medals to those who were stopped at the 25.7 mile mark. The day after the race Blake Windsor picked up one for his wife and surprised her with it.

If you ask Juli Windsor, however, she’ll be picking one up herself next year.

“I have the determination to come back and do it again because I would hate to see such evil overshadow the human desire to triumph,” Windsor said. “Running and marathons and all of that are such a celebration of human life. Why should something so evil overshadow that and taint that?”