Massive AT&T network outage disrupted service for tens of thousands on Thursday, causing inability to call, text, access internet.

Outage affected AT&T wireless customers nationwide; over 70K reported issues on DownDetector at peak. 

911 services impacted in some areas; people urged to use landlines if possible. Caused major disruptions. 

AT&T said outage was not caused by cyberattack, but by incorrect network upgrade process. 

FBI, FCC, DHS investigating outage, in touch with AT&T. Looking into root cause, any malicious activity. 

AT&T took immediate action, steadily restored service. Fully fixed after 12 hours. Apologized, ensuring it won't happen again. 

Customers furious over lack of info during outage. AT&T shares fell 2% despite market highs. 

911 outages could bring AT&T fines. But no evidence yet of attack. Industry says issue with call handoffs. 

White House involved, pushing for answers. Critical telecom infrastructure must be resilient. 

Massive reliance on mobile devices makes outages dangerous. Backup plans key for emergency communications.