Ten horses were killed and a Denver-area hunter/jumper barn was destroyed in a fire that broke out early Monday morning.

The fire destroyed an almost 32,000-square-foot barn and indoor arena at Hidden Pines Farm in Franktown, Colorado. The farm is owned by Dana Vollbracht, a lifetime member of the Colorado Hunter Jumper Association. It was home to trainers Sarah Watson, Suzy Balenseifen and Elizabeth Joseph and their clients.

The fire was reported just before 4 a.m. Monday, Nov. 27. A caretaker at the barn was able to get four horses out of the burning building before being overcome by smoke and taken to the hospital, where he was treated for smoke inhalation and released, according to a report from Franktown Fire Protection District. It took firefighters from four fire companies 3.5 hours to put out the blaze.

In a Facebook post Monday, Vollbracht said the four surviving horses are being treated at Littleton Equine Medical Center.

“In the early morning hours today, my worst nightmare was realized when a fire destroyed Hidden Pines Farm, taking 10 special horses from our tightknit barn family,” she wrote. “Four horses survived due to the heroic efforts of Eddie and Felipe. These horses are now recuperating with the best of care at Littleton Equine Medical Center. I am grateful for those who rallied to transport them for me. My broken heart has yet to find the bottom of this kind of grief, it’s endlesss…. Bottomless.”

CHJA has started a fundraiser through the Colorado Hunter Jumper Foundation to help those affected by the fire. In a statement, Watson thanked the horse community for it’s support: “Watson Equestrian is heartbroken over the tragic loss of our beloved horses and appreciate the outpouring of love and support our community is providing.”

The cause of the fire is under investigation.