A Connecticut woman has passed away from breast cancer only 18 hours after her wedding.  

Dressed in a brown wig and a beautiful white wedding dress, 31-year-old Heather Mosher said her vows to her 35-year-old husband David from her hospital bed at St. Francis Hospital and Medical Center in Hartford.

The couple met at a swing dancing class in 2015, and became engaged on Dec. 23, 2016. It was the same day Heather was diagnosed with cancer, but David decided to propose to her anyways, after enjoying a horse-drawn carriage ride.

"She didn't know I was going to propose to her that night, obviously, and I said to myself, you know, 'She needs to know that she's not going to go down this road alone,'" David told CBS Hartford affiliate WFSB.

Sadly, by September 2017, Heather's cancer spread, and the couple were unsure if Heather would make their Dec. 30 wedding date.

"We found out it was in her brain and a couple months later, she was on life support with a breathing tube," David said. "She was tough. Anyone else would have given up a long time ago. The doctors even said we don't know how she's still here."

The pair decided to move up their wedding date to Dec. 22, and they were wed in front of family and friends. Despite Heather saying vows in a hospital bed and hooked up to a ventilator, the ceremony went off without a hitch.

"It was just like surreal because I'm supposed to be exchanging vows to her and here I am saying goodbye," David told ABC News.

Sadly, their original wedding date ended up being the day of Heather's funeral.

"We were losing her as we were all standing there thinking to hold on to this, because it was it. ... What we were seeing, what she was giving us, what she was giving him, was the last of what she had to give," bridesmaid Christina Karas said.

We're keeping David and his family in our prayers during this difficult time.