Steph Solis

USA TODAY

Authorities in northern California were trying to determine Sunday what caused the death of two skydivers in a tandem jump Saturday, one of whom was 18 and whose family watched as he hit the ground.

Officers found the bodies in a field near the Skydive Lodi Parachute Center in Acampo, the San Joaquin County Sheriff's Department said in a statement. The parachute did not appear to deploy until after impact.

The other victim was an instructor, according to Deputy Les Garcia. He did not release the names.

"The parachute failed to eject properly. We have no explanation why," Bill Dause, owner of the Parachute Center, told KCRA-TV. "The only thing it looks like is something may have gone out of sequence (and) that may have caused the problem."

The 18-year-old was jumping for the first time and had a brother and several other people with him at the skydive center, Dause said. The instructor was a skydiving veteran who had about 700 previous jumps, he said.

The wind and other conditions were "perfect" at the time of the jump, Dause said. "Conditions had nothing to do with it."

Deputies received a 911 call around 10 a.m. from someone reporting a skydiver hit the ground without an open parachute, according to the statement. The Federal Aviation Administration will investigate the cause of death.

The Parachute Center, which opened in 1964, is based in one of the largest drop zones in the U.S., according to the business's website. It offers an introductory jump, in tandem with an instructor, from 13,000 feet for $100.

Experienced skydivers can jump for $15.

The skydive center was in the news in May, when a small plane carrying 17 skydivers landed upside-down after clipping a pickup. The worst injuries were minor cuts and scrapes.

Saturday's deaths marked the second fatal jump at the Parachute Center this year. In February, a solo skydiver was killed when a parachute malfunctioned.

"We didn’t do anything wrong,” Dause told KCRA-TV. "It's a love of the sport. You keep going. You feel sorry for the people who can't participate any longer."

Contributing: John Bacon, Greg Toppo, USA TODAY