(Bloomberg) — Engineers are trying to find out why two steelbolts broke off from the 47-story London tower known as theCheesegrater, falling five floors to the street.

The base of the unoccupied building on Leadenhall Street in theCity of London financial district was cordoned off after theincident, which caused no injuries, according to a statementyesterday from owner British Land Co. Each bolt is about 1 meter (3feet) long, a spokeswoman said.

“There is no risk to the structural integrity of the building,”said British Land, the U.K.'s second-largest real estate investmenttrust.

London's new crop of skyscrapers, with nicknames such as theShard and the Walkie Talkie, have sparked controversy because oftheir impact on the city's skyline and after design faults werediscovered. The Walkie Talkie at 20 Fenchurch Street drew crowds ofonlookers last year after reflected sunbeams were hot enough tomelt parked cars. Developer Land Securities Group Plc said in Junethat it received planning approval to install a system to reducethe reflections.

Contractor Laing O'Rourke Plc and structural engineers ArupGroup Ltd. have examined the Cheesegrater, officially named theLeadenhall Building, and are inspecting the broken bolts. Theresults are expected in about 10 days, British Land said.

British Land and Oxford Properties developed the Cheesegrater,which is due to open next year. Aon Corp., the largest insurancebroker, and Amlin Plc have agreed to lease space in thebuilding.

–With assistance from Neil Callanan in London.

Copyright 2018 Bloomberg. All rightsreserved. This material may not be published, broadcast, rewritten,or redistributed.