A "power event" at Google Cloud's London-based computing operations disrupted banks, courts and websites across the UK on Tuesday, leaving customers of Lloyds, HSBC and Revolut unable to pay or move money for hours, the Guardian reported. Google said the failure hit its "europe-west2-b zone," according to the Guardian.

Services began coming back around 1 PM London time, or 8 AM Eastern time, and were back for most customers by 3 PM London time, Google said, according to the Guardian. In a statement Tuesday evening, a Google Cloud spokesperson said it had resolved a disruption "at a third-party facility in our europe-west2 cloud region due to a power event," the BBC reported.

Revolut said its sign-up, sign-in, card payment, transfer, ATM and crypto services were hit but that customers' money and data were safe, the Guardian reported. By 5 PM London time, only six of the 27 Revolut services listed on its website were working, according to the Guardian. Revolut later said its services were fully restored, the BBC reported. Users in the UK, Ireland, France, Spain and Japan reported problems, Euronews reported.

The video system used for remote court hearings in England and Wales failed throughout the morning, which was believed to have delayed several hearings, the Guardian reported. Royal Mail and the parcel company DPD were among other services hit, the BBC reported.

The Financial Conduct Authority said it was engaging with Google and affected firms to understand the impact, the Guardian reported. Meg Hillier, who chairs Parliament's Treasury committee, asked regulators for an initial response by November 4, according to the Guardian. Google said it would publish an analysis after an internal investigation.

The outage came exactly a year after an outage at Amazon Web Services' largest cloud site knocked more than 1,000 sites offline, including UK banks, the BBC reported. Revolut says it has more than 80 million retail customers, Euronews reported.

What we know: A power problem in Google Cloud's London region disrupted banks, Revolut and court hearings for hours before services were restored.
What we don't: What caused the power problem and how many payments failed.