Although the matter is still under investigation, everything now points to the grim fact that the father of the five children who perished in the Omagh blaze was responsible for their deaths. The PSNI is treating the incident as murder, and Arthur McElhill is the chief and sole suspect.
The shockwave which swept across Tyrone and Northern Ireland when news broke of Tuesday morning's house fire has now turned to a sense of bewilderment. How could a man murder not just his wife but all five of their children as well, before taking his own life?
What was it that prompted Mr McElhill to sprinkle petrol around the family home before setting light to it and incinerating the house and all its inhabitants? Why did he refuse to make any attempt to escape, even when rescuers were within sight?
Although the implication that Mr McElhill must have had ready access to a petrol can suggests an element of pre-meditation, something must have flicked the switch that turned the 39-year-old stockman from a seemingly loving father into a crazed arsonist and mass murderer.
As detectives and forensic experts piece together the missing pieces of the jigsaw, and try to establish what happened and why, the public has to wait and wonder. But the suggestion that he was suffering from depression after leaving prison in 1999, half-way through a three-year sentence for indecent assault, may have some bearing on this tragic episode.
Given his background, there will inevitably be questions for the police and social services to answer. Were sufficient follow-up checks kept on Mr McElhill? Did his partner, Lorraine McGovern, ever express concern to the authorities about his behaviour?
Those closest to this catastrophe deserve answers. Members of the McGovern family circle suffered one major shock by being told of the fire. Today, they - and the McElhill family as well - are having to come to terms with the enormity of what now seems to have taken place.
As the McGoverns and the McElhills make arrangements to lay their loved ones to rest, they will need compassion and understanding. The bouquets of flowers and the messages of support left at the scene of this disaster should give them an indication of the extent of support.
The PSNI is to be commended for keeping the public in the picture as events have unfolded. By speedily establishing the likely scenario they have helped the public to make some sense of this very human tragedy.
This has been a fast-moving story and people following it are entitled to feel bemused. Unfortunately, there are no winners in this unhappy saga, just a deep sense of sadness and sorrow.