Obviously, at this stage, a definite answer cannot be given to that question but let us see what happened with a couple of previous inquiries.
The Hillsborough Stadium Disaster occurred on 15th April 1989. Lord Justice Taylor - (later Lord Chief Justice) - was appointed to inquire into the events on that fateful day. He issued his interim report in August 1989. Here is a link to the report. His final report is dated January 1990.
The Bradford City Stadium Fire occurred on 11th May 1985. Mr Justice Popplewell chaired the inquiry and issued an interim report in July 1985 with a final report in January 1986.
Those examples demonstrate the reports can be produced quickly when it is possible to identify at an early stage safety matters requiring urgent attention but it is essential that findings are accurate and recommendations are sound.
Many other examples of inquiries could be mentioned. For example, the Ladbroke Grove Rail Inquiry investigated the accident of 5th October 1999. A Scottish judge - Lord Cullen - conducted the inquiry and the report was in two parts. Part 1 (19th June 2001) looked at the causes of the crash and the circumstances in which it occurred and made recommendations for safety improvement. Part 2 considered management of safety and the regulatory regime. The recommendations of the Cullen inquiry led to the creation in 2003 of the Rail Safety and Standards Board and in 2005 of the Rail Accident Investigation Branch in addition to the Railway Inspectorate. Standards-setting, accident investigation and regulation functions were henceforth clearly separated, on the model of the aviation industry.