Authorities say a parachute failed to fully open during a tandem jump at a northwestern Ohio skydiving center, killing an instructor and his student.

Witnesses say instructor Daniel Mathie and student Sierra Thomas spiraled to the ground Saturday night. They landed in a field near the Cleveland Parachute Center and were pronounced dead at the scene.

Portage County Sheriff David Doak says the parachute cords may have been tangled, causing the main canopy to only partially open.

The 30-year-old Mathie and 22-year-old Thomas were one of two tandem teams that jumped from an aircraft at about 8,000 feet.