Ocado was forced to cancel thousands of orders after a fire caused by colliding robots broke out a fulfilment centre in Erith.
Fire crews fought the warehouse blaze on Church Manorway for nearly 12 hours on Friday, first arriving on the scene shortly after 12.30pm, working until 2am.
Around 800 staff were evacuated from the fulfilment centre, Ocado's largest, which handles up to 150,000 orders a week.
Fortunately, there were no reports of any injuries.
The company said it was "working to restore normal service as soon as possible".
A spokesperson said: "We expect the facility to begin operating within the coming week and thank customers whose orders are affected for their patience.
"We would like to also thank the London Fire Brigade and all the other emergency services for their hard work and professionalism in dealing with this incident."
Shares in the company slipped by about 3% today, the BBC reports.
The fire started after three robots used to pick up groceries on a grid and deliver them to members of staff for boxing crashed into each other.
The damage was reportedly limited to less than 1 per cent of the grid, having been contained.
We're really sorry. Due to a major incident at our Erith warehouse some of our orders have been cancelled. Please be patient with us while we manage this. If this impacts your order, we will be in touch. Thank you.
— ocado (@Ocado) July 16, 2021
Speaking on Saturday, Station Commander Steve Vydelingum said: "Firefighters worked hard in hot and arduous conditions inside the warehouse. Around 800 staff evacuated before the Brigade arrived.
“There were no reports of any injuries.
“The fire is very deep seated, and firefighters will continue to be at the scene into Saturday (17 July) damping down hot spots."
A similar incident took place at an Ocado warehouse in Andover, Hampshire, two years ago.
A grid robot caught light due a battery charging unit fault, sparking a blaze which lasted for four days.
The site, which processed 30,000 orders a week, has since been rebuilt.
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