One person was critically injured and thousand of cattle have reportedly perished after a huge explosion and large fire broke out at South Fork Dairy in Dimmitt, Texas, on Monday night. Following numerous 911 calls about an explosion and fire as well as trapped employees, the Castro County Sheriff’s Office, the Dimmitt, Hart and Nazareth Fire Departments responded to the farm.

According to the Castro Country Sheriff’s Office Facebook page, one person was trapped inside when crews arrived. Fire crews were able to locate the person who was then flown to the University Medical Center in Lubbock. Several reports also suggest that numerous individuals were treated for injuries on the scene.

Dimmitt Mayor Roger Malone told local news ABC 7 that the explosion was heard several miles away. The large plume of smoke was visible on radar for 30 minutes and could also be seen more than 30 miles away in Hereford.

The total number of cattle affected by the fire is unknown, but news outlet KFDA 10 out of Amarillo was reporting Tuesday afternoon that upwards of 18,000 perished in the fire.

“At this time, we know only a small percentage of the cows at the facility survived,” KDFA reported.

The cause is still under investigation, but reports say the fire started in the dairy milking building.