An explanation is still not forthcoming as to why a window at the top of Norman Foster's Swiss Re building fell out, almost two weeks after the glass panel plummeted 120m to the floor.
Details of the potentially catastrophic incident - which occurred last Monday morning (18 April) - remain firmly under wraps, and many of those involved, including the architect, are keeping tight-lipped.
However, it is understood that client Swiss Re is taking the matter extremely seriously.
At the time of going to press, the plaza around last year's Stirling Prize winner was still cordoned off for safety reasons.
No one was injured when the panel crashed from the 28th storey to the ground below. The accident happened in the early hours of the morning when the area was deserted.
Nevertheless, staff working in the half-empty tower are having to enter the building under a covered walkway in case of further falls. Investigators are checking each of the other 743 opening windows for faults and, it is believed, they may even examine all 6,000 panels covering the 180m-high tower.
A spokeswoman for the company managing the building, at 30 St Mary Axe, insisted there would be a full inquiry into the incident.
She said: 'We have never had anything like this happen before - it is not an ongoing problem and we are not laying the blame on anybody at this stage.' Foster and Partners refused to comment.