A burning crane has fallen over on a construction site at Broadway, closing a major road.
The Lend Lease crane operator managed to escape the blaze.
Fire fighters are warning of massive traffic delays and are urging people to avoid Broadway and Wattle Street at Ultimo.
A witness has told News Limited that they heard the crane cable snap one by one.
Broadway traffic has been closed in both directions.
Reports claim up to twenty workmen on the University of Sydney site were forced to run for their lives.
More to come