The downside to cloud services is that they're of absolutely no use when they're not available. Today Google Docs, Drive, Sheets, and Slides have all been unavailable for some of the people that have come to depend on them.
Google is aware of the issue, and it's showing a service disruption for each service on its apps status dashboard page. This is delineated in the screenshot below by the presence of an orange icon next to Drive, Docs, Sheets, and Slides.
The tech giant says that it is still working on the issue, and it will provide a report later on detailing what caused things to go wrong. Until then, affected users will just have to wait. Service can pop back in at any time, and some people who were previously impacted are already seeing things work as expected again.
Update: Google has gotten everything worked out. Here's the final word from Mountain View.
The problem with Google Docs should be resolved. We apologize for the inconvenience and thank you for your patience and continued support. Please rest assured that system reliability is a top priority at Google, and we are making continuous improvements to make our systems better.