Investigators are examining whether a fire that swept through a Homebase store could be linked to a blaze at another DIY store half-an-hour earlier.
About 90 firefighters tackled the blaze at South Aylesford Retail Park in Kent on Saturday afternoon.
Shoppers and staff fled as flames ripped through the unit and spread to the neighbouring Carpetright shop. Detectives are investigating whether there is a link to a small fire at a B&Q store in nearby Larkfield.
Police have confirmed the fire is being treated as suspicious.
Kent Police said the fire at the Aylesford site was brought under control by about 2100 BST but the building was structurally unsafe. It said it was also investigating a small fire at a B&Q store about two miles away, at about 1315 BST, which staff were able to put out. Det Ch Insp Jon Clayden said: “It is too early to say if these incidents are linked.
“We are continuing our investigations to establish the cause of the fire at Homebase and part of that investigation will be to determine if there is a link between these incidents.” Homebase was evacuated and emergency teams called to the scene at about 1245 BST after a fire alarm was activated. A store manager said at the time and there were around 50 shoppers in Homebase and about 30 shoppers in Carpetright.
Carpetright assistant manager Rob Rattenbury said the fire sent thick plumes of smoke 50ft (15m) into the air. He said: “We heard the alarm going off in Homebase so I got on the tannoy right away and told our customers to evacuate the store immediately.
“No one panicked, everyone just walked out calmly.” He added: “Homebase is completely wrecked.”
At its height about 90 firefighters, 17 fire engines and several support vehicles were used to tackle the flames. John Pereira, Kent fire service area manager, said crews remained at the scene damping down. “Although the main fire is out, there are still some small pockets of fire which we are tackling from the outside because the building is structurally unsafe and can not be entered,” he said.
The area around the store has been fenced off to allow other stores on the retail park to open as normal. During the fire, witnesses reported seeing smoke three miles away in East Malling.