Southwest Airlines issued a nationwide ground stop Friday morning, reportedly following a technical issue with its computer systems.

Passengers began reporting delayed flights as early as 5:30 a.m. (EST) via Twitter. The airline also responded to many travelers via the social media platform, apologizing for the “inconvenience” and assuring customers the technical team was working to fix the issue.

This just the latest issue amid the carrier’s ongoing cancellations due to maintenance-related issues, and an FAA investigation that’s been going on for over a year.