Police said a body found in the charred ruins of Newcastle's Kard Bar shop, the scene of a severe fire on Tuesday, is that of Brian Sandells, 81, who lived in a flat above.
Rescue workers said that while he has not been formally identified, Sandells had not been in contact with his family since the fire, which occurred in Cross Street, in the heart of the city.
Police said the extent of the damage made the search extremely difficult, but they confirmed the discovery of Sandell's body on Wednesday afternoon.
Firefighters are still working to establish the cause of the fire, which was brought under control on Tuesday night.
Superintendent Bruce Storey said: "This is a very difficult and complex investigation due to the nature and severity of the damage caused to the building and detectives are working alongside specialist fire investigation officers and structural engineers to carry out enquiries as to how and why the fire started.
"We are extremely saddened to say that we believe that Brian Sandells, who was a resident in one of the flats above the shop, was inside his home at the time the fire happened and may have passed away during the fire. Our thoughts are with his family and friends and we working to try confirm this for his family."
Assistant chief fire officer John Baines of the Tyne and Wear Fire and Rescue Service (TWFRS) said: "Our thoughts and sympathies go out to the gentleman's family and friends at this very sad time.
"Business owners always need to be vigilant especially in the run up to Christmas when there is increased stock and customers which can increase the risk of fire."
Most residents in Cross Street have now been allowed to return to their homes after being evacuated yesterday, although some local businesses remain shut.
Firefighters responded to a call at 8:48am on Tuesday, and by 11am smoke was visible across the city.
Nearby streets were closed and the immediate area evacuated.
This is Kard Bar, which sells greeting cards and posters.
Assistant chief fire officer John Baines said in a statement at the time: "We are tackling a severe fire in a building in Newcastle city centre and we have deployed more than 55 firefighters and 11 appliances (fire engines) and two aerial ladders.
"I'd ask members of the public to avoid the area for the time being. We understand this will cause some congestion in the city centre and would like to thank the public for their patience as we deal with the incident."
Northumbria police also told people to avoid the area.
One witness posted this video of the fire soon after it broke out.
When the #fire first broke out in #Newcastle at Charlotte Square. @EveningChron @metroradiouk
Carly Jade, who shot the video and works at a nearby digital agency, told BuzzFeed News she first smelled smoke when she got to work before 9am, but didn't realise how serious the situation was.
"There were a few firemen trying to get into the front door of the shop, and smoke slowly coming through the roof," she said. "The few firemen spent a good half an hour trying to get the door open – when they eventually did, there was another door they had to get through. By then, the smoke had got worse and we started seeing ash flow into the air.
"We were evacuated from the building at around 9:50am. When we got out the building the whole of Charlotte Square was filled with smoke, with more police cars and a few fire trucks on the scene.
"By the time we got back into the building at around half 10, the smoke turned black but we still couldn't see signs of fire. Then a few minutes later, the fire had broke out, which is when I took the video, and smoke started to fill our office, which we then had to evacuate again."
In this video shot from a building opposite and posted to Twitter, Phillip P. Penaluna demonstrated how fierce the fire was.
Stuck in the i6 building opposite the fire from the smoke. It's not looking good like #kardbarfire
Flames could be seen at the top-floor window.
Huge flames can be seen throughout the floors of the flats above Kard Bar on cross street
Huge flames are creeping out of the roof
Streets around the scene of the blaze were engulfed in smoke.
Firefighters at Newcastle city fire | Fears people are trapped inside shop | Live updates: https://t.co/ulBlYnIHWb
Jonny Scott, 35, whose band Kylver had merchandise stored in the building next to the one on fire, spoke to BuzzFeed News.
"In the building next store there is a skate store and a taxi office," he said. "We store all our merch – CDs, T-shirts, hats – in our office in the building, which has an adjoining wall to the one on fire.
"In terms of value there's a couple of hundred quid of merch in there. If that's gone we have to start from scratch."
Images tweeted by the fire service hint at the structural damage to the building.
Over 55 Firefighters,11 fire engines & 2 aerial ladder platforms working to keep the fire in Cross St. under control