A devastating blaze that tore through a garage building and the homes next to it will remain a crime scene while an investigation is carried out.
The fire broke out at motor parts supplier Wrightway Car Parts, in Newcastle Road, West Boldon, at 8.20pm yesterday and spread to two adjoining homes.
Nearby homes and the Red Lion pub were evacuated by police as a 100m cordon was put in place.
The A184 was closed last night and has reopened again this afternoon. All fire engines have now left the scene.
Now fire officers have confirmed exploding gas cylinders landed in neighbouring properties.
Fire investigation teams and crime scene investigation units are now at the scene as a probe is launched to determine the cause of the blaze.
More than 40 firefighters tackled the blaze which took more than six hours to bring under control and extinguish.
One neighbour, who asked not to be named, said the owner of the garage also lives in the property next door - which was gutted in the blaze.
Group manager Richard Rickaby said: "As you can see from the front, the damage is quite significant. When you actually go into the property and towards the rear, the commercial part of the property goes quite far back - around 100m.
"That's very fire damaged, there's a significant amount of cylinders that have been involved in the fire. Some of those have actually exploded and landed in neighbouring properties.
"The fire itself spread from the commercial premises into the domestic accommodation through a door in the garage and it spread into a neighbouring premises through the roof.
"It was an extremely difficult fire to fight and I must praise the firefighters and the officers in charge who managed the situation safely together with our friends the police who put up a cordon and evacuated neighbouring properties - to maintain residents' safety.
"In hindsight looking at the damage there today and the location of some of the cylinders that was a good decision made at the time in the heat of the moment.
"I'll be here for the majority of the day trying to investigate how the fire actually started and establish how it spread to the neighbouring premises.
"I'm here with the crime scene investigation team and Northumbria Police to investigate the fire. It will remain a crime scene until we're happy with our findings."
A spokeswoman for Northumbria Police said: "Inquiries are ongoing and any residents with concerns are asked to speak to a nearby officer."