The ANT Lab (Analysis of Network Traffic), based at USC Viterbi's Information Sciences Institute (ISI), has detected a significant internet outage in Chile following a massive power failure that plunged much of the country into darkness on Tuesday, February 25, 2025.

The ANT Lab continuously monitors global internet activity by scanning approximately 5 million networks every 11 minutes. This active probing methodology allows researchers to detect and analyze significant changes in internet reachability in near real-time. 

John Heidemann, principal scientist in the networking and cybersecurity division of ISI and research scientist at USC, noted the severity of the outage. “I got an outage alert from our system and took a look at our website,” he said. “The alert showed a big outage in Santiago, and by the time I looked, there were outages all over the country.” 

Reuters reported that the Chilean government subsequently declared a state of emergency and implemented an overnight curfew from 10 p.m. to 6 a.m. across much of the country. According to Chile's Interior Minister Carolina Toha, the blackout was caused by a transmission line failure in the country's north. Officials ruled out a cyber attack as the cause. 

The ANT Lab's data shows that internet connectivity in Chile began to recover starting around 11:00 p.m. Chile time on February 25th, with network availability returning to pre-outage levels by approximately 3:00 a.m. Chile time. 

“Running near-real-time monitoring of the Internet is important because it can provide rapid information about the extent of problems like what happened in Chile,” Heidemann said. “I could tell right away that this was a widespread outage, and I was able to see Chile recover about eight hours later.”

This latest monitoring event follows the ANT Lab's detection of a major outage in Bangladesh last July during civil unrest, where approximately 96% of that country’s networks went offline for several days. 

What strikes Heidemann is that both Bangladesh and Chile suffered country-wide outages.  “Many countries have power problems, but taking a whole country out for several hours is very unusual,” he said.

Recent and historic outage data is available on the ANT Internet Outage Maps page.