It happened on the A1 near Dunbar.
Worker Dead After Queensferry Crossing Tragedy
A construction worker has died on the site of the new Queensferry Crossing.
Another worker also suffered "minor injuries'' in the incident on the north tower deck at about midday on Thursday.
Work on the site has stopped while the incident is investigated.
A Police Scotland spokesman said: "We are currently working alongside our partner agencies to investigate an incident on the Queensferry Crossing bridge that resulted in a man sustaining fatal injuries.
"The call was received around 12.20pm on Thursday and, sadly, the man was pronounced dead a short time later. Another man on the bridge also sustained minor injuries.
"Enquiries to establish the full circumstances surrounding this matter are ongoing.''
The £1.4 billion bridge is set to open in December. Work started in 2011 and the death is thought to be the first fatality at the site.
A spokesman for the Queensferry Crossing project said: "We are deeply saddened to have to confirm there was an incident just before noon on April 28 on the Queensferry Crossing's north tower in which a person has lost his life.
"One other person has been taken to hospital. All activity has been stopped at the north tower.
"Our thoughts are with the family and friends of our colleague and co-worker at this time.''
It is understood the worker was a 60-year-old man and was struck by the boom of a crane he was directing.
Construction workers' union UCATT said the death was a poignant reminder of the dangers in the construction industry on Workers' Memorial Day.
Regional secretary Harry Frew said: "UCATT sends its sincere condolences to the family of the worker who has suffered this tragic accident. It is impossible to imagine how they must be feeling.
"UCATT will be doing everything it can to find out how and why this accident occurred and to ensure that similar fatalities are prevented in the future.''
The 26 year old was first targeted in Briarscroft Road.
Euan Johnston was shot in his car last month.
The family of three crash victims took their case for the 59-year-old to be put on trial to the Appeal Court in Edinburgh earlier this year.
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