One of the data centers hosting Amazon’s infrastructure cloud services had a power outage Thursday evening, creating issues for customers that lasted until about 5:30 am Pacific Friday, according to status updates on the dashboard for Amazon’s Elastic Compute Cloud (EC2) service.

The outage caused downtime for customers with massively popular web services, including Pinterest, Heroku, Quora, Foursquare and others, according to news reports. Provider of cloud-based platform services for programmers Heroku, for example, reported widespread eight-hour outages of its production and development infrastructures, according to its status dashboard online.

Amazon said the issues were caused by a power outage but did not provide any more details about the outage’s root cause. “As a result of the power outage tonight in the US-East-1 region, some EBS volumes may have inconsistent data,” the company said.

The company’s east-coast data center infrastructure is in northern Virginia. Amazon is very secretive about exact locations of its data centers, so it is hard to say where exactly in Virginia the offending data center is.

The cloud is also hosted in data centers in northern California, Oregon, Sao Paulo, Dublin, Tokyo and Singapore, according to the Amazon Web Services cloud status dashboard.

An Amazon spokeswoman did not respond to a request for comment in time for publication.

Because the company’s cloud services are extremely popular and widely used, an issue at one of its data centers usually quickly resonates around the world, affecting providers of online services and their customers. The number of people affected by such outages is nearly impossible to estimate because of the long food chain of services built on top of services, with Amazon’s infrastructure at the bottom.

One of the most recent high-profile Amazon cloud outages happened in August 2011, when a data center in Dublin lost power. The incident was initially blamed on a lightning strike, but the utility that was providing electricity to the data center later denied that lightning was the culprit.

Amazon’s typical response to customers affected by such outages is instructing them to build better-distributed cloud infrastructures, replicating virtual servers and data across multiple geographically separated physical data centers.