8 major IT disasters of 2024

Millions of missed calls

While the CrowdStrike outage was huge, it was dwarfed in sheer numbers by a February service interruption at AT&T Mobility, affecting 125 million mobile devices across the US. The outage, lasting more than 12 hours, prevented about 92 million calls from being completed, including 25,000 911 calls, according to the US Federal Communications Commission. An equipment configuration error was the cause of the massive outage.

While it took AT&T close to two hours to roll back the network change, restoration of full service took at least 12 hours because the mobile carrier’s device registration systems were overwhelmed with the high volume of requests for re-registration onto the network, the FCC said.

Then in June, AT&T customers reported another service outage. Reports of service outages began to spike at 1 p.m. EST on June 4, then declined around 6 p.m. The areas surrounding New York City, Chicago, Philadelphia, Dallas, Pittsburgh, and Indianapolis were apparently affected.