This is a problem frequently found with survivors of any incident - if I had died, then maybe someone else could have lived.
Many surivors experienced trouble from families who had lost children.
For one survivor, a girl aged 8, one neighbour said about the disaster - It took all the roses and left the thorns behind. Very reassuring I'm sure, for a child of that age !
In a situation of depest grief, there is no excuse to be so vitriolic. People in the Valleys have the reputation of looking after each other. In this case, this was not so.
For the person who said this, hopefully there is still time to apologise. Likewise for any other person who has been unkind in any way, an apology is never too late.