Upwards of 73,000 AT&T clients were cut off from making mobile calls and sending text messages following the nationwide outages that began Thursday around 5 AM ET. This comes on the heels of AT&T's temporary outages over the last few days, including a 911 blackout in some parts of the southeastern United States.

Verizon and T-Mobile customers were also hit with service interruptions, but not as hard as AT&T. About 4,000 customers reported cell phone outages for Verizon, while around 1,900 T-Mobile customers reported a lack of service.

People started reporting the outages on the website, "DownDetector," which tracks telecommunication issues throughout the U.S. Initially, the number of reported AT&T outages fell during the 5 AM hour, only to spike again in the 7 AM hour.

In San Francisco, the Department of Emergency Management issued a public announcement, saying that its 911 center was functioning.

However, in their statement posted to X, the officials suggested that AT&T customers use a landline or a rival phone service to get through to them if the mobile network was down.

They also wrote, “We are aware of an issue impacting AT&T wireless customers from making and receiving any phone calls (including to 911). We are actively engaged and monitoring this.”

People online are making comparisons to Julia Roberts' Netflix film "Leave The World Behind," which follows a family dealing with the reality of a country-wide blackout crisis.

So far, AT&T, Verizon, and T-Mobile have not officially commented on what triggered the outages ... but AT&T says they're currently working on customer complaints.