An inquiry chaired by a Supreme Court judge closely examined three different theories but found there was insufficient evidence to determine any one of them as the cause.
The inquiry, chaired by Justice Leveson, continues.
It is unclear when the official inquiry, chaired by Sir Peter Gibson, a former appeal court judge, will begin hearing evidence.
A major public inquiry into the handling of the construction, chaired by the former Lord Advocate, Peter Fraser, was established in 2003.
The British government also set up an independent inquiry, chaired by Lord Justice Bingham, in 1992.
If there is a valid objection that is not withdrawn, an inquiry chaired by an inspector will take place.
And the answer is this bloody inquiry chaired by Lord Leveson.
Ben-Gurion scheduled closed hearings with a new board of inquiry chaired by Haim Cohn, a supreme court justice.
The inquiry, chaired by Justice Margaret Cameron, was called in May 2007 and released a report in March 2009.
This uncertainty led to a second inquiry, chaired by High Court judge, Sir Daniel Brabin, which was conducted over the winter of 1965-66.