Kathleen Lumsden, 76, a retired printer, said she was "really shocked and very, very saddened," adding: "They were our neighbours for about six years and both Yvonne and Michael were very friendly and good people.
"Michael's going to feel dreadful when he comes back. He's always been a good neighbour to me so I will do as much as I can to help him.
"He was very lucky to have survived but I don't know if he'll think he's been lucky."
Kathleen said Mr Rennie, a grandfather, worked away from home during the week returning to the marital home at weekends. The couple are thought to have been married for about two or three years and had previously lived in Dundee.
The Rennies' next door neighbour Linda Kettles added: "They are very, very nice people who kept themselves to themselves.
"They'd gone on holiday to enjoy themselves. They only get the weekends together. I'm totally devastated by the news. I feel for their families."