They met online, at age 18.

He had cystic fibrosis. So did she.

Their disease — a terminal genetic disorder that damages the lungs — should have kept them from ever meeting face-to-face, ever hugging or kissing or even touching. Doctors warn strongly against close contact between CF patients because they can swap dangerous bacteria, jeopardizing their health.

The two ignored such warnings. They were in love.

She kissed him the first time she saw him, leaning against a brick wall at a Dairy Queen, reported CNN. He’d driven six hours from his home in St. Charles, Mo., to hers in Flemingsburg, Ky.

Two years later, Katie and Dalton Prager married. They were 20 years old.

In the early years of their marriage, they experienced nearly everything together — Burkholderia cepacia, the highly contagious infection Dalton passed to Katie, just like doctors predicted; their first home in Kentucky, near Katie’s family; their rescue dogs; vacations; surgeries; IV drips; matching oxygen tanks; the lung transplant list.

Dalton got his new lungs first, in November 2014, and the couple was kept separate until Katie got hers eight months later, after a grueling insurance battle.

In profiles of the couple, CNN and other local media called the Pragers a “real ‘Fault in Our Stars’ couple,” a reference to the John Green novel that chronicles the love story of two cancer-stricken teenagers.

But soon, Katie’s transplant began to fail. Dalton developed lymphoma. So did she. He contracted pneumonia and was placed on a ventilator at Barnes-Jewish Hospital in St. Louis. She entered end-stage renal failure and, in early September, began receiving hospice care at her family’s home in Kentucky.

“The past week has been very emotional and decisions have been made that aren’t meant to be made by someone in their 20s with their whole life ahead of them,” she wrote on the couple’s Facebook, Dalton and Katie Prager’s Transplant Page. “… There are too many things going on in my body to be able to fix everything. Things appear to be going downhill faster than I thought they would. My hospice nurse is coming out today to get everything set up. I won’t have to go back to the hospital or get anymore IVs. I get to spend the rest of my time surrounded by people and things that make me happy. Please don’t take this as a sign of me giving up. It’s the last thing I want people to remember of me.”

Before she died, Katie had one last wish: to see her husband in person.

Local media rallied behind the couple, who had been reported on extensively in past years, and soon thousands of dollars were donated to transfer Dalton from St. Louis to a hospital near Katie. To see her, he’d need to first get off the ventilator, but regular Facebook post updates from Katie and Dalton’s mother, Renee, made it sound like the reunion was a real possibility. Dalton had been on a ventilator before. For CF patients, machines and surgeries and invasive tubes are not extraordinary.

On Sept. 11, his mother wrote on the couple’s Facebook page and called her son a fighter.

“He told me before he was not going to die in the hospital but surrounded by loved ones,” she wrote. “He’s making sure of it with God’s help!”

More updates followed.

“God is great!” Dalton’s mother wrote Sept. 12.

“I have awesome news to report!!!” Katie echoed. “… They are expecting to be able to transfer him most likely tomorrow which is amazing!”

The next day, the transfer had stalled again. On Sept. 14, a new update relayed yet another setback. The same Sept. 15.

The page went dark for two days, until Sept. 17, on Saturday, the day Katie’s family planned to celebrate an early Christmas for her, since it was her favorite holiday and there was no guarantee she would live to December. Relatives draped her aunt’s home in decorations, reported the Lexington Herald-Leader, and former co-workers decorated a tree with twinkling lights.

Katie pulled on a Christmas cat sweater, according to the newspaper. Music filled the room.

But Katie remained quiet. Despite the flurry of family and friends around her, she was newly alone.

Hours before, she FaceTimed her husband from his hospital bed in St. Louis and watched him die.

Dalton and I got out of the hospital today! We're both very happy to be out! I will update again soon. Thanks for your love and prayers! -Katie

Posted by Dalton and Katie Prager's Transplant Page on Monday, December 14, 2015

“She told him that she loved him,” Katie’s mother, Debra Donovan, told CNN. “We don’t know if he heard her.”

Dalton passed at 12:56 p.m. He was 25.

“My angel, my best friend, the love of my life, my husband went to be with the Lord our God today,” Katie wrote on their Facebook page Saturday afternoon. “Dalton fought a long hard battle with Cystic Fibrosis. He was a courageous fighter and ‘give up’ wasn’t in his vocabulary.”

In the same post, his mother, Renee, added: “You may Breathe Easy now my son. You are my true hero.”

Dalton loved to cook and preferred being outdoors, according to his obituary. He was a traveler and student of American history, an interest that bled into other hobbies, like antiquing and collecting guns, knives, hats and watches.

“Dalton always enjoyed the opportunity to dress nice and look sharp!” his obituary read. “He was a social person who knew no strangers in life. His memory will live on in the hearts of many.”

On the couple’s Facebook page and in a personal blog, the Pragers chronicled the highs and lows and living with cystic fibrosis. When one was going under the knife, the other would assume the role of official updater. They often discussed their faith.

In one post from October 2014, titled “Pray,” Katie confessed she was having a particularly trying day.

“It’s hard enough having one end stage CF patient, let alone two,” she wrote. “It’s hard to focus on me when all I care about and want to focus on is Dalton. Please pray for us. For peace, so that our minds will stop racing. For wisdom, to make all the right choices when it comes to both of our health. For time, the most precious thing of all. We need more time. More time together. More time of loving. More time for cuddling. More time for being each other’s best friend. More time for laughter. We refuse to stop fighting for ourselves and for one another. Please pray.”

And though the average life expectancy is close to 40 years for those who can avoid the dangerous bacteria that lead to lung infections, Katie told CNN the day before Dalton died that she doesn’t regret foregoing the medical warnings to kiss him at the Dairy Queen.

“It gave me some of the best years of my life,” she told CNN. “I’d rather have five years of being in love and just really completely happy than 20 years of not having anybody.”

Correction: An earlier version of this report had an incorrect reference to the last name of Katie and Dalton Prager.

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