T-Mobile is dealing with a service disruption in the United States, with many customers reporting problems on their iPhones. One of the most visible signs for users is the “SOS” indicator appearing in the status bar instead of normal cellular service.

According to the report, the issue appears to be affecting customers across the country. The outage has drawn attention from iPhone users who noticed they could no longer connect normally to T-Mobile’s network while the carrier worked to address the problem.

In a statement cited by 9to5Mac, a T-Mobile spokesperson said the company’s teams were actively working on reports of technical challenges impacting some customers. The carrier indicated that service impacts were being investigated as those reports continued.

For now, the main takeaway is that the disruption is tied to T-Mobile network issues rather than a device-specific iPhone problem. As T-Mobile continues its response, affected users may keep seeing SOS mode until normal service is restored.