The north side of the Park Plaza Westminster Bridge roundabout was closed to traffic following a fallen crane on the building site.
As a precaution emergency vehicles were called shortly before 9pm on Thursday night.
York Road was closed southbound as well as Westminster Bridge Road. Long queues of traffic quickly built up on Westminster Bridge.
Meanwhile a police helicopter with a searchlight hovered until after 10pm.
The incident comes just two days after the hotel was topped out by Mayor of London Boris Johnson.
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