One man has died and another is in a serious condition after they collided while skydiving, the ambulance service said.
Emergency services went to Sibson, near Peterborough, shortly after 3.30pm on Saturday, the East of England Ambulance Service NHS Trust (EEAST) said.
Despite EEAST and air ambulance crews working hard together to try to save one of the men's life, he was pronounced dead at the scene, a spokeswoman said.
Another man, in his late 20s, suffered serious spine and leg injuries and was flown to Addenbrooke's Hospital, Cambridge, where he arrived in a serious but stable condition.
Cambridgeshire Police said that the man who died was in his early 50s. The other man is in his 20s.
The Peterborough Telegraph newspaper said the dead man was 53 and from London while the survivor is 28 and from France.
They reportedly collided about 50 feet above the ground.
The BBC said that Sibson airfield is one of two bases for UK Parachuting, which offers skydiving courses and charity jumps.
Callers to UK Parachuting were referred to the British Parachute Association, who were not immediately available for comment.