An experienced skydiver has been killed while taking part in a 222-person group-formation jump trying to set a world record.
The accident happened on Thursday (local time) when the victim's main parachute malfunctioned, a spokeswoman for the Arizona skydiving facility said.
The skydiver, who was not immediately identified, was declared dead at the scene at SkyDive Arizona, about 105km south of Phoenix.
"The malfunctioning parachute was released too low to allow the reserve parachute to fully open," said Jocelyn Bernatchez, a SkyDive spokeswoman.
Bernatchez said the airplane involved was functioning properly, and that weather conditions in Eloy, Arizona, were good at the time of the accident, which occurred about 7.30am local time.
The skydivers were on their first attempt to break the record when the mishap occurred, said Gulcin Gilbert, a spokeswoman for the World Team group that organised the jump.
The team of 222 veteran skydivers from 28 countries had come to the popular US facility to try to break the record for the largest number of people to complete two aerial formations before deploying their parachutes. The previous record, involving 110 skydivers, was set last year in Florida.
Organisers said safety was foremost in their minds in their planning and execution of the complicated manoeuvre, an effort that had been 18 months in the making.
Under the plan, skydivers in multi-coloured jumpsuits are taken aloft by 10 planes and have 80 seconds to complete the kaleidoscope-like formations before opening their chutes.
Skydivers were to be at an altitude of about 19,500 feet (6000 metres) during the record-breaking attempt, with an average free-fall speed of about 190 kmh.
Thursday's accident marked the third skydiving death in more than four months stemming from an attempt to break a record in the sport.
In the same facility last December, two skydivers were killed after colliding at a height of 200 to 300 feet (61 to 91 metres) and falling to the ground in what authorities ruled an accident.
Briton Keiron O'Rourke, 40, and Bernd Schmehl, 51, of Germany, were part of a group of 200 skydivers from another organization trying to break the double-formation record.