Ocado's massive robot controlled warehouse in Hampshire was destroyed by fire on Tuesday (Feb 5).
The fire broke out in the early hours of Tuesday morning as more than 200 firefighters struggled to keep it under control.
"There are still pockets of fire", said a spokesman for Hampshire Fire and Rescue Service.
Walworth Industrial Estate still remains under lockdown and a no go area to the public as many businesses have been forced to remain closed as the fire spread to the second building.
It said that due to concerns over the presence of pressurised refrigerants at the site, the police conducted a limited evacuation of the immediate area on Wednesday evening.
News today that the fire at online delivery firm Ocado's robotic order-fulfilment warehouse has been put under control, and no longer regarded as a 'major incident, ' will be welcomed by Ocado customers and of course the firm itself.
Hampshire Fire and Rescue Service said four firefighters had been treated for slight smoke inhalation.More news: China has this warning after Modi visits Arunachal Pradesh
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The online grocery giant said: "We apologise to all those affected by this incident and are very thankful to the people of Andover for their understanding and support during this hard period".
Firefighters have been tackling the blaze for almost 40 hours.
Ocado said part of the roof collapsed overnight, but it confirmed no members of the Ocado team or the public were injured. Makes you truly appreciate the fearless men and women of the Fire Service!
Ocado stressed it has comprehensive insurance for the property, stock and equipment and for business interruption losses.
The online grocer's shares were down 7% on Thursday after it said it would see a fall in sales growth until it can shift operations to other warehouses.
Ocado said on Thursday it was working to minimise disruption for customers by increasing capacity at its three other major British sites.
The centre had been providing about 10 percent of Ocado's United Kingdom capacity and used the robotic technology that the firm is selling to retailers around the world.