Verizon released a statement after more than 100,000 wireless outages were reported nationwide Monday morning.

“We are aware of an issue affecting service for some customers,” Verizon said in a statement to NBC News. “Our engineers are committed and we are working quickly to identify and resolve the issue.”

The statement comes about three hours after the website Downdetector received a flood of reports of Verizon outages in Chicago and beyond.

As of 9:30 a.m., Downdetector showed more than 4,000 Verizon outages in the Chicago area. By 10:30 a.m. the number of reports had fallen to around 2,700, the website said.

Nationwide, the site recorded more than 105,000 Verizon outages as of 10:30 a.m. An outage map from Downdetector on Monday showed the “most commonly reported” outage locations are Chicago, Indianapolis, Minneapolis, Phoenix, Omaha, Cincinnati, Denver, Seattle and Columbus.

Dozens of comments from Verizon users on the site said their phones were turning “SOS” mode on and off, leaving some unable to send or respond to text messages or make calls.

Other comments on Verizon's social media pages also noted that Verizon phones were reportedly in SOS mode.

The carrier responded to some comments, at times asking for more detailed information from those who had reported their phone in SOS.

“I know I would share your concern if my phone was also in SOS mode,” Verizon said in a response. “I am here to help you investigate this and find a solution. When did this problem first appear? Can you tell us the nearest cross streets and towns where the problem occurs? Please send a direct message.”

What is SOS mode?

According to Apple, the SOS message appears when “your device is not connected to your cellular network,” but it also means you can make emergency calls over other cellular networks.

The feature is only available in the US, Australia and Canada.

“When SOS appears in your iPhone’s status bar, it means a cellular network is available for emergency calls,” the company says.

Anyone who calls with SOS is automatically redirected to a local emergency number and their location is passed on to the emergency services.

Users can also set up their phones so that their phone notifies emergency contacts after an SOS call with a text message that includes their current location – and updates those contacts if that location changes.

“On iPhone 14 or later (all models), you can even use Emergency SOS via satellite to text emergency calls when cellular and Wi-Fi coverage is unavailable,” explains Apple.

This is a developing news story that will be updated.