The website Downdetector has detected a surge in outage reports from users of AT&T, Verizon, T-Mobile, Consumer Cellular, Boost Mobile, US Cellular, and Straight Talk. 

Outage reports for the carriers began around 0345 ET. Geographically, the outages have been reported across some major US cities. 

Users of Downdetector began reporting AT&T outages around 0345ET. 

Downdetector users say AT&T outages are widespread across the southern part of the country. 

Users of Downdetector began reporting Verizon outages around 0400 ET. 

Verizon outages are concentrated in major Northeast metro areas. 

Users of Downdetector began reporting T-Mobile outages around 0350 ET. 

A cluster of Downdetector users report outages in New York City. 

Here's what X users are saying:

*The situation is developing, and there are no concrete reports on what has triggered widespread cell outages.