An elderly couple have been found dead in their home.
The bodies of Ken and Edna Fisher were discovered at the Washington bungalow where they have lived for 38 years by their carer yesterday morning.
Northumbria Police’s major crime team have now launched an investigation.
And as detectives await the findings of a post-mortem examination, neighbours on Biddick Villas in Columbia have paid tribute to Ken, 76, and 74-year-old Edna.
A woman who lives nearby, but asked not to be named, said: “They were lovely people. They have got two daughters and a son and their son is on holiday.
“They have lived in that house for 38 years. They are lovely neighbours”.
Emergency services descended on the usually quiet street at around 10.30am yesterday.
Neighbours spoke of seeing police, paramedics and firefighters outside the large well-maintained bungalow.
Workers from Northern Gas Networks were also present.
The home was cordoned off with police tape, and yesterday afternoon forensics officers in white overalls got to work inside.
Local people told The Journal that Edna and Ken had two daughters and a son.
They said Edna, who worked at a local family planning clinic until her retirement, had been suffering from dementia in recent years and that her husband had looked after her with the help of a carer.
One man, who is in his 60s, said: “It is just so sad. They were a really nice couple, very pleasant sort of people, and they had three children.
“It was such a shock this morning. I came in from the gym and the street was full of fire engines and police cars. I believe she had dementia for some time and he had been caring for her but they also had a carer coming in.”
Police were last night still working to establish exactly what went on inside the Fishers’ home.
But Det Chief Insp Christina Barrett, who is leading the investigation, does not believe anyone else was involved.
She said: “This investigation is at an early stage. However, there is nothing to suggest there is any threat to the wider community.
“Early indications are that no one else has been involved in these deaths but our inquiries continue to establish exactly what has taken place.
“Anyone with information they believe could assist us is asked to come forward.”
And Chief Insp Dave Willett, from the force’s Sunderland Area Command, has also moved to reassure worried residents.
“I understand people may feel concerned following this incident and will have officers in the area to offer reassurance,” he said.
“Anyone with concerns should speak to officers on patrol or by calling their local Neighbourhood Policing Team.”
Coun Linda Williams, who represents Washington Central, said: “It’s very unsettling but until the whole story is out there it’s very difficult to make a judgement.
“I am sure when anything like this does happen the police will be out door to door.”
Anyone with any information about the deaths should call Northumbria Police on 101 extension 69191, quoting log number 371 11/04/14.