Arizona police believe equipment failure is to blame in the death of Dr. David Stather, a Calgary doctor who died after BASE jumping with a wing suit near the Grand Canyon.

CTV Calgary’s Elissa Carpenter said police believe Stather’s death was a tragic accident, and are looking at equipment failure as a cause of death as Stather’s parachute never opened. Carpenter said a medical examiner in Arizona performed a full autopsy on Monday to confirm the cause of death.

Stather, 41, who worked as a pulmonary specialist at the University of Calgary lung clinic, had done a successful BASE jump with two of his friends on Friday morning before hiking up the cliff to attempt another jump. His friends waited at the bottom to watch, but Stather never returned.

Stather’s friends then hiked back to the top of the cliff.

“They looked down into the canyon along the flight path and they thought they could see approximately 2,000 feet down, his bright red wing suit that he was wearing,” Det. Pat Barr with the Coconino County Sheriff’s Office in Arizona told CTV Calgary.

Similar to skydivers, BASE jumpers use parachutes to break their fall, but rather than jumping from an airplane, they jump from fixed objects such as buildings or cliffs.

Police arrived at the scene Friday night, and a rescue helicopter recovered Stather’s body on Saturday. Stather was confirmed dead from injuries resulting from a fall trauma, police said.

Stather’s parents, who live in Guelph, Ont., have made arrangements to have their son’s body returned to Canada.

Dr. Alain Tremblay, who worked with Stather, described his colleague as “really not someone that’s replaceable.”

And Tremblay said the energetic doctor always put his patients first. “He’s the type of person that if you had a problem, he would not let go until that problem was solved and every avenue was explored.”

“If you see some of the pictures of him, he’s always smiling,” Tremblay added.

With a report from CTV Calgary’s Elissa Carpenter