"The outage appeared to have begun around 12:35 pm ET, according to Catchpoint Systems, a digital experience monitoring company. Operations were fully recovered by 4:49 pm ET, Amazon said. The Seattle-based company did not comment on the cause of the outage.

"The most common causes of this type of outage are software related, said Lydia Leong, a cloud analyst with Gartner. "Either a bug in the code or human error. Right now we don't know what it was."

"The system that went down was the first of what now are three AWS regions in the United States. It is still the largest and is also where AWS rolls out new features, "so it's disproportionately big," she said."