The online retailer Amazon has apologised for a fault in its web hosting service EC2, which knocked out many well-known websites.
Last Thursday's outage caused sites including Foursquare, Reddit and Quora to go offline, some for days.
EC2- Elastic Compute Cloud - provides processing power and storage to companies that do not have their own data centres.
The apology comes after a week of silence on the matter.
Amazon is giving users a 10-day cloud services credit, whether or not they were affected.
Cloud computing is a fast-growing business that is becoming essential to increasing numbers of businesses and individuals, who use it for remote storage of data.
It offers individuals and businesses the ability to rent virtual storage space.
Cloud providers like Amazon host websites and other data in server farms.
A statement on Amazon's website said: "We know how critical our services are to our customers' businesses and we will do everything we can to learn from this event and use it to drive improvement across our services."
Amazon promised to "spend many hours over the coming days and weeks improving our understanding of the details of the various parts of this event and determining how to make changes to improve our services and processes".
In a detailed technical explanation the company described what had gone wrong with its data storage process.
It said there was a problem when changing a network configuration, which caused its primary and secondary systems to fail and overload.
Amazon then had to stop the system and restart it, including physically moving servers.
Amazon's statement on Friday said: "Everything looks to be getting back to normal now."
It concluded with: "Last, but certainly not least, we want to apologise."