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.
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.
For the latest local news and events direct to your inbox every Monday, you need our weekly email newsletter SE1 Direct.
7,000+ locals read it every week. Can you afford to miss out?
Read the latest issue before signing up