Thousands of Verizon users across the United States reported having little or no cellphone service on Monday morning in major cities, including in Atlanta, Chicago, Denver, New York and Phoenix. According to the website Downdetector, which tracks user reports of internet disruptions, more than 104,000 cases of Verizon outages were reported across the country as of 11:20 a.m. Eastern, more than an hour after the first issues were reported. A map posted on the site showed cities with the most reports. On the site, many users said their cellphones were intermittently displaying “SOS” mode and that they could not place calls or send or receive text messages. “We’re aware of the issue affecting service for some customers,” a spokesperson for Verizon, Ilya Hemlin, said in a telephone interview at 11:30 a.m. “Our engineers are engaged and we are working quickly to solve the issue,” he added. Hemlin said he had no information on the cause of the problem or whether it was linked to localized power failures in certain parts of the country. He said the company would provide more information as soon as it was available. On social media, where Verizon customers went to check if outages were widespread, Verizon technical support was only responding individually to scores of users reporting the “SOS” problem on Monday morning. Related Articles National News | What to watch as JD Vance and Tim Walz meet for a vice presidential debate National News | The Latest: Helene’s death toll rises to more than 100 as supplies rushed to isolated communities National News | Kris Kristofferson dies: Singer-songwriter and actor was 88 National News | John Ashton dies: “Beverly Hills Cop” actor was 76 National News | Trump escalates attacks on Harris’ mental fitness and suggests she should be prosecuted Many people on the social media platform X complained of how the outage would affect their ability to do jobs, such as deliver Instacart orders. Verizon, one of the largest cellphone carriers in the world, has 114.2 million wireless subscribers in the United States. This article originally appeared in The New York Times.