Technology is great until…it’s not. As many kids started back to school online, Zoom experienced outages Monday morning.

Starting around 9:00 a.m. ET, the outages mostly affected the United States, especially the eastern seaboard, as well as Atlanta and Chicago. Users reported not being able to get into their scheduled meetings, while others experienced no problems.

The outage lasted a few hours, with all issues being resolved about 3 hours later.

The CEO of Zoom, Eric S. Yuan, issued an apology over Twitter for the major outage, saying:

Today @zoom_us had a service disruption that affected many of our customers. We know the responsibility we have to keep your meetings, classrooms & important events running. I’m personally very sorry & we will all do our best to prevent this from happening in the future.

Many Twitter users joked that “Zoom Days” might be the new snow days as many students experience online learning. Zoom is averaging over 300 million daily users since coronavirus necessitated working from home earlier this year.