It was reported the man had fallen from a height, the Northern Ireland Ambulance Service says.
Image source, PAA man in his 30s has died after an accident while helping to build a bonfire at a site in County Antrim, police have said.
The Northern Ireland Ambulance Service (NIAS) said it had responded to reports a man had fallen from a height.
It happened at the Antiville bonfire in Fairway in Larne at about 21:30 BST on Saturday.
A rapid response paramedic, two emergency crews and a doctor were dispatched.
The bonfire, constructed from stacked wooden pallets, is more than 50 feet tall.
It is one of many being built across Northern Ireland ahead of the traditional July celebrations.
They are lit in areas to mark the Eleventh night, which take place annually ahead of the Twelfth of July.
It is part of the commemorations to mark the victory of the Protestant King William of Orange, over the Catholic King James the second at the battle of the Boyne in 1690.
The Reverend Ben Preston, of Craigy Hill Presbyterian Church, said he had been to the scene.
“As a church, our deepest condolences are with the family and community of Antiville and Craigy Hill,” he said.
“No-one involved in this kind of thing expects that to happen – the community is in shock and is numb,” he told the BBC.
“The community gather around the family and we remember them in our thoughts and prayers.
Image source, PA
“Our thanks go to the Ambulance Service, PSNI, and Fire and Rescue Service for their work tonight,” he added.
Democratic Unionist Party (DUP) MP for the area Sammy Wilson, who attended the scene on Saturday night, said the community was in shock.
“My thoughts and sympathy are with this man’s family,” he told the PA news agency.
“It is a real tragedy at what is a special time of year for people in the loyalist community.
“The family are well-known in the area, and I am sure this will be greatly felt within the community.”
Image source, Pacemaker
Alliance assembly member (MLA) for East Antrim Stewart Dickson said “a young man died after falling from a 11th night bonfire being built in Antiville”.
“My deepest sympathy goes to his family and friends and the whole community as it reflects on this tragic death,” he said on Twitter.
Insp Adrian Bryan said police were appealing for witnesses to the “tragic accident” who were in the area last night.