A Missouri zookeeper was killed Friday morning when the elephant he was trying to herd into a barnyard knocked him over and crushed him against the ground.

John Bradford, 62, who had been a caretaker at Dickerson Park Zoo in Missouri for 30 years, died on impact when the elephant he had managed for decades suddenly lunged through the chute connecting the barn stalls to the barnyard. Cora Scott, a spokeswoman for the city, said that the fatal incident took place when Bradford and a guide tried to herd the 41-year-old female through the 12-foot passageway. No other zoo employees were injured.

“At approximately 8:45 a.m., Springfield Police and emergency responders were dispatched to Dickerson Park Zoo in response to an accident that occurred in the zoo’s elephant container,” Scott wrote in a joint statement released Friday. “Senior zookeeper and elephant manager John Phillip Bradford, 62, and other staff were handling an elephant when the accident occurred.”

The elephant, whose name is Patience, has been at the Dickerson Park Zoo since 1990. Paul Price, Bradford’s friend and former co-worker, told local media that the senior zookeeper was deeply invested in Patience, and that elephants were his passion. For many years, he worked hard for the animals’ safety and welfare.

"He was always aware of dangers and everything and was instrumental in developing the elephant management program at the zoo at the national and international levels," he said.

A second statement detailing the tragedy indicated that Patience had been exhibiting hesitant behavior since the October death of Connie, the matriarch of the elephant herd. For this reason, Patience was kept under close watch for several days prior to the incident. She will not be euthanized, and no disciplinary action will be taken, the Associated Press reports.

According to a 2012 assessment by the Association of Zoos and Aquariums (AZA), Dickerson Park Zoo provides more than adequate living space for its elephants. The zoo also complies with the organization’s guidelines for the proper care and handling of elephants.

“The facilities and program provide a complex and stimulating physical and social environment,” AZA inspectors wrote in their report. “During the inspection visit, natural behavioral activities, positive social interactions and appropriate activity levels were witnessed with all of the animals.”