T-Mobile is experiencing a nationwide outage, with thousands of users across the United States reporting service disruptions. Many customers say their phones have switched to SOS mode, leaving them unable to make calls or use mobile data.T-Mobile down. (UnSplash)See the outage map here.Downdetector reportsAccording to Downdetector, reports of the outage began surging around 4:30 p.m. EDT on Monday. Users from across the United States, including California, New Jersey, Washington, Utah, Florida, Minnesota, and New York, reported issues ranging from a complete loss of signal to mobile internet outages.One user reported, "SOS here in northern UT for about 5 minutes."Another wrote, "Why is my phone in sos in Melbourne fl what is going on I just joined this company I’m so upset."A third user added, "No data in Minneapolis, can't call out. Very frustrating."Another reported, "I've got no service and no internet connection. NYC."One longtime customer expressed frustration, writing, "I've had a cell since the mid-nineties. Never lost service for this long! Starting to rethink getting another landline with all the crazy going on."As of now, T-Mobile has not publicly acknowledged the outage or provided an estimated timeline for when service will be restored.