A number of bolts from the 'Cheesegrater' skyscraper in London will be replaced as a precautionary measure after a third fell off in recent months.
British Land, which owns the 47-storey Leadenhall Building in the City of London, admitted a third bolt dropped off the building and was captured by precautionary tethering put in place last year after two steel bolts broke last November.
All bolts have now been checked and an investigation ruled that a process called hydrogen embrittlement lead to the material being cracked.
British Land said it will now replace a number of bolts, which measure in at just under one metre, as a precautionary measure.
The investigation by contractor Laing O'Rourke and structural engineer Arup added there was "no adverse effect on the structural integrity of the building".