While Office365 and Active Directory services were hit, other services like Visual Studio Team Services, Xbox Live and OneDrive also experienced problems, the website Geekwire reported.
Engineers have restored power to the datacenter and recovered a majority of network devices. Some services are starting to see signs of recovery, mitigation efforts continue. Updates: Portal - https://t.co/66mR6nPbwY Status Page - https://t.co/Dw19fIGsXf and/or Twitter. pic.twitter.com/dkmT24IVfr— Azure Support (@AzureSupport) September 4, 2018
On its Azure status website — which was inaccessible for a while — Microsoft said there were "two identified impact workstreams".
"Customers with resources in South Central US may experience difficulties connecting to resources hosted in this region. A complete list of impacted services can be found below.
It said the root cause was a series of lightning strikes that occurred near one of the South Central US data centres. This led to a voltage increase that affected cooling systems.
"Automated data centre procedures to ensure data and hardware integrity went into effect and critical hardware entered a structured power down process," the company said.
"As a result, non-regional services, such as Azure Active Directory, encountered an operational threshold for processing requests through the South Central US data centre. Initial attempts to fail over into other data centres resulted in temporary traffic congestion for those regions."