Two tandem skydivers fell to their deaths when their main and reserve parachutes opened only partially, authorities said.

Paul Joseph, 30, and Reed Michael Loeschke, 28, were found just before noon Sunday in the yard of a vacant home in southern New Jersey and were pronounced dead at the scene.

Joseph was an instructor at Freefall Adventures, a skydiving school. He and Loeschke were making a tandem jump, a practice in which an instructor and inexperienced diver are tied together, authorities said.

The jump, which took place around noon, was from a plane owned by Freefall Adventures, police said. Staffers from Freefall Adventures would not comment on the accident.

Autopsies were expected to be performed Monday, and the Federal Aviation Administration was also investigating.

Freefall Adventures, which boasts on its Web site that it has introduced more than 250,000 people to recreational skydiving, has had fatal accidents before, including two deaths in a July 2005 jump. The company has operated at Cross Keys Airport for more than 20 years.

In 2005, 27 people died in parachuting accidents in the U.S., according to the Fredericksburg, Virginia-based United States Parachute Association.