United Airlines issues a ground stop for flights nationwide due to a 'systemwide technology issue'

• United Airlines has issued a nationwide ground stop, the company confirmed with Insider. 
• All United flights are being held at their departure airports due to a "systemwide technology issue." 
• The airline is currently investigating the issue, a spokesperson for the company said. 

United Airlines has issued a nationwide ground stop due to a "systemwide technology issue," a company spokesperson told Insider.

All United flights are being held at their departure airports. Airborne flights will continue to their destinations as planned, the spokesperson said.

"We're currently investigating and will share more information as it becomes available," the spokesperson added.

Stranded passengers affected by the ground stop in Denver, San Francisco, Kansas City, Houston, Dallas, and Washington, D.C. are posting on social media about their experiences, with one user writing they've been on the "tiniest hottest plane" all day.

This story is developing. Check back for updates.