His party colleague, Sinn Féin councillor John Hearne, also knows the family and described it as a “terrible tragedy”.
Hearne told BBC News NI that residents living in the estate noticed the blaze at about 05:00 and they went out to wake up their neighbours to try to help.
But he said it “all happened so fast” and was “hugely distressing for everyone involved”.
Independent councillor Donal Barry had also been working with the family very recently.
Speaking to the BBC’s Evening Extra programme, he was audibly upset by their deaths.
“Only last Thursday I was speaking to Kim on the phone in relation to a matter I was dealing with,” he said.
“As soon as I went up there this morning and I looked and saw the house, my heart sank. I knew who it was then.”
Barry said the immediate family were “well thought of” in Waterford and the community has been “numbed” by the attack.
The councillor added that there was “devastation” in local schools where the couple’s children were pupils.
He praised the efforts made by the local council which set up a support hub at Butler Community Centre in St John’s Park in the aftermath of the attack.
“Waterford City and County Council won’t be found wanting in any support which they can give the community,” he said.
