It was reported late on Monday that thousands of T-Mobile customers across the United States had service interruptions that stopped them from making or receiving phone calls, sending or receiving text messages, or accessing the internet.

Although the wireless provider claims that most services are up and running, there have been reports of service disruptions in major locations including Chicago, Los Angeles, Las Vegas, Phoenix, New York, and Seattle.

There were as many as 83,000 users hit at 10 p.m. on Monday. According to DownDetector, an Eastern Time zone-based outage tracking service that gathers service reports from users via supplied data, it is currently 8:00 p.m. T-Mobile has not provided any information regarding the number of affected users. About nine thousand of them vanished overnight, never to be seen again.

Arizona, California, Colorado, Florida, Hawaii, Kansas, Nebraska, North Carolina, Oklahoma, Texas, and Washington are just some of the states that have filed user complaints.

Several Twitter users have complained that, following a recent disruption in service, their phones are now permanently stuck in “SOS mode,” rendering all except emergency calls impossible.

Without specifying the nature or duration of the outages, T-Mobile tweeted that the firm was looking into the issues and working to resolve them.

In a tweet, T-Vice Mobile’s President of Technology Neville Ray said the business was working “rapidly” to fix a “3rd party fiber interruption issue” that had been “intermittently disrupting certain phone, message, and internet services in various regions.”

On Monday night, two of the most popular wireless companies, T-Mobile and Verizon Wireless, both experienced temporary disruptions. Verizon and AT&T both received over 1,200 reports of disruptions at their peak.

Attempts to reach T-Mobile, AT&T, and Verizon via their customer support lines were immediately disconnected.