A number of Americans are dealing with cellular outages on AT&T, Cricket Wireless, Verizon, T-Mobile and other service providers, according to data from Downdetector.

A Facebook post from the Cook County, Minnesota Sheriff's Office on Thursday morning stated that some local residents are experiencing a service outage as well. The post states that "The companies are aware and are working to resolve the issue. If you experience no service and need to call 911, please use a land line. Wifi calling is still available."

AT&T had more than 64,000 outages this morning, in locations including Houston, Atlanta and Chicago. The outages began at approximately 3:30 a.m. ET. The carrier has more than 240 million subscribers, the country’s largest.

“Some of our customers are experiencing wireless service interruptions this morning. We are working urgently to restore service to them. We encourage the use of Wi-Fi calling until service is restored,” AT&T said in a statement.

Cricket Wireless had more than 13,000, the outage tracking website said Thursday. Verizon had more than 4,000 outages and T-Mobile had more than 1,900 outages. Boost Mobile had about 700 outages.

“Verizon’s network is operating normally. Some customers experienced issues this morning when calling or texting with customers served by another carrier. We are continuing to monitor the situation,” Verizon said.

T-Mobile said that it did not experience an outage.

“Our network is operating normally. Down Detector is likely reflecting challenges our customers were having attempting to connect to users on other networks,” T-Mobile said.

So far, no reason has been given for the outages.