A skydiver was killed and another injured after the two collided midair during a group jump in Washington state, authorities said this week.

The Adams county sheriff’s office said in a statement on Monday that authorities were called Sunday evening regarding reports that “two skydivers were needing medical attention”.

“On scene, deputies learned of a midair collision resulting in one of the skydivers becoming deceased and the second sustaining injuries requiring additional treatment at a medical facility,” the sheriff’s office said.

In a later statement on Monday, authorities said that they were investigating the fatal incident, which they said “occurred at West Plains Skydiving” during a “scheduled group jump”.

Investigators identified the skydivers as Randy Hubbs, of the Kennewick area, and Nicole Klein, of the Colville area, and said preliminary findings indicate “an in-flight collision occurred between the two skydivers during descent”.

After the collision, authorities said Hubbs “reportedly became incapacitated and was no longer in control of his parachute canopy”.

Staff members observed and tracked Hubbs “from approximately 500 feet above ground level as he drifted north and away from the designated drop zone”, according to the sheriff’s office. Witnesses told authorities that he “appeared unresponsive, with his head and arms down, before disappearing beyond a hill northeast”.

Officials said that weather conditions were not considered “a contributing factor in the incident”, and a total of 11 individuals participated in the jump operation.

“We offer our deepest condolences to those impacted by this incident,” the sheriff’s office said.

West Plains Skydiving said in a statement shared with local outlet KHQ-TV that “at approximately 1,000 feet above the ground, and with neither jumper aware of the other’s position, the two parachutes came into contact”.

“The Skydive West Plains community is mourning the loss of a friend who has been part of the drop zone family for nearly a decade,” the company said. “The team’s thoughts are also with the second jumper and her family as she recovers.”

The company added that Hubbs had completed more than 800 previous jumps, and that Klein had completed 900.