The horrific blaze which engulfed Grenfell Tower and led to appalling loss of life has caused a deep sense of shock and raises searching questions as to how it is possible for such a disaster to occur in an age of rigorous fire regulations.
That such a catastrophe should take place in a modern, affluent and developed city such as London is almost beyond comprehension.
Of course, the chief consideration today is for those who have died and suffered serious injury and for the residents who have lost everything in the space of a few hours.
Harrowing eyewitness accounts of desperate people jumping from the burning building or throwing their children out of windows in the hope they might be saved, are absolutely heartbreaking.
The thoughts and prayers of everyone on this island will be with the bereaved and injured at this traumatic time as well as the emergency workers in London who have had to deal with yet another major incident.
While the investigation has already begun into the cause of this blaze - with reports suggesting it may have started with a faulty fridge - there will be an intense focus on how the fire was able to take hold and whether recent refurbishment work to the exterior was a factor in its rapid spread.
Questions will also be asked about the safety precautions in place at this 24-storey tower block which, like so many others, was built in the 1970s.
We are told that residents repeatedly raised concerns about fire safety but were reassured by the management organisation.
A fundamental rethink may be needed with regard to the standard advice for tower blocks, that people should remain in their apartment in the event of a fire and wait to be rescued.
A number of those who escaped said if they had heeded this advice they would not have survived.
At the very least there needs to be a review of safety at high rise structures which were constructed some decades ago and which may need to be urgently upgraded.
The installation of sprinklers and the provision of safety measures such as extinguishers and smoke masks for residents must also be considered.
There are major issues for all housing authorities in the wake of this tragedy, including the Northern Ireland Housing Executive which needs to take on board the lessons of Grenfell Tower and earlier tragic fires.
The safety of every resident must be a priority following this devastating blaze.
