One horse is dead and another is recuperating after being attacked by a swarm of bees in Arizona last month.

Prescott, Arizona, Fire Department Division Chief Fire Marshal Don Devendorf said fire personnel responded to a call from a woman reporting that she and a companion were being attacked by bees on April 27. Upon arrival, firefighters discovered the women’s’ heads and faces covered by hundreds of bees. Four horses in a nearby corral were also covered in bees, Devendorf said.

“The women and the animals were all being stung aggressively,” he said.

The women were transported via ambulance to a nearby hospital emergency room, where they were treated for multiple bee stings and released.

Meanwhile, crews sprayed the horses with a soap and water firefighting mixture to remove the bees, but the swarming continued, Devendorf said.

“The bees usually die the minute they are sprayed, but as soon as we would spray the horses, the bees would cover their heads and necks again,” he said. “Finally, we were able to make some makeshift halters and get the horses out of the enclosure.”

Firefighters removed the horses from the scene and continued to spray them. A veterinarian called to the scene determined that two of the horses sustained only minor stings. The practitioner determined the other two were in critical condition and they were taken to a veterinary clinic for treatment.

“One horse died at the clinic, the other recovered,” Devendorf said.

Devendorf said the incident might have involved Africanized bees, a hybrid resulting from cross-breeding Western honey bees and African honey bees. Africanized bees are known to attack any human or animal that unwittingly enters its territory, although incidents involving such bees are unusual for the Prescott area, he said.

“We’re up in the mountains, and Africanized bees are not supposed to be this far north,” he said. “I’ve been here for 30 years and I’ve never seen anything like this.”

Some dead bees were recovered from the scene and sent to the University of Arizona for study.