A bull apparently killed a Northern California rancher and then was shot dead when it threatened first responders, authorities said.

The incident occurred Thursday afternoon in rural Contra Costa County, the San Francisco Chronicle reported.

A report of an unresponsive rancher lying in a field drew sheriff’s deputies, firefighters and an animal control officer to the scene, said Steve Aubert, a fire marshal public information officer with the East Contra Costa Fire Protection District.

“It is believed that the bull may have attacked the rancher,” Aubert said.

The bull approached emergency personnel in a threatening manner and deputies shot it to protect them, Aubert said.

The county medical examiner will determine the cause of death of the rancher, whose identity was not released.