Tower Bridge was closed to road traffic and pedestrians on Thursday night after part of the LED lighting one of the upper walkways came loose in the high winds of Storm Emma.
The damage – on the downriver side of the bridge – was discovered late on Thursday night.
City of London Police cordoned off the bridge to motorists, cyclists and pedestrians whilst river traffic was diverted away from the central span of the bridge.
The lighting system on the bridge was installed six years ago – at no cost to taxpayers – for the Queen's Diamond Jubilee and the Olympic Games.
The project was a partnership between the City of London Corporation, the Greater London Authority and London 2012 sponsors EDF and GE.