Condolences to them mate, its the lowest place ive ever been and i hope your nephew and partner take advantage of any help theyre offered because talking really does help. time does help but will never heal.
Biggest thing for me is with there job it's not a case of having to buy more sand, replace a door or get a new light fixture (like it would be for most peoples fuxk ups at work) it is people's lives that are lost and I would say they should be more accountable but I also know its not done with malice and they're only human.