Editors at Billboard.com report the 47-year-old man, who suffered from a pre-existing heart condition, collapsed during the event and was treated by onsite medics before being taken to a nearby hospital, where he died.

The festival's emergency services director Carl Monzo says in a statement, "Those who were with him informed our medical team that he was suffering from a pre-existing cardiac condition and, unfortunately, we understand that he has died. The safety and security of our patrons are our top priority, and our medical staff responded flawlessly. Our sympathy goes out to his family and friends."

The festival was headlined by Billy Joel and Mumford & Sons.