Unfortunately, it usually takes about a year before the investigation becomes public and final.
The typical investigative report reveals: no HAZOP and a last minute or temporary change to a procedure being verbally handed down between shifts. Pompous plant management, as expected, is outraged at the discovery of how business is actually being done at thier plant and loudly proclaims that there will be a thourough investigation and that this sort of thing will never happen again....!!!
Then everyone goes back to the way that they were doing things all along. Mangers get promoted/bonuses etc..... and we wait for the next disaster.