Some Chicagoans who use the internet provider RCN were reporting an outage Monday afternoon.
The company acknowledged on Twitter around 11 a.m. that "a select group of customers, who recently rebooted their cable modem, may be experiencing a service disruption."
"Our crew is working hard to restore services as quickly as possible," the tweet read.
A number of Twitter users responded by saying they were still experiencing an outage without rebooting their modem.
In some replies, RCN said the issues could be "part of a known outage."
Users reported issues particularly on the city's North Side, in the Lincoln Park, Lakeview, Roscoe Village, Uptown, and Wrigleyville neighborhoods.
"We're aware of a known issue in the area affecting service," the company tweeted in one response. "While an estimated time of repair is not available, we appreciate your patience while this is being resolved."
Callers contacting RCN were also being told the company was "aware of an outage."
Details on how far the outage stretched or how long it would take to fix remained unclear.
RCN did not respond to NBC Chicago's requests for comment.