Hi,
When the computers shut down//failed/was were down, there was a crisis in the office.
Do all of the bolded terms fit in the above and mean about the same to you?
I used to work in the computer business years ago. Terminology may have changed, but here's my take on this.
shut down A shut-down sounds intentional, eg for maintenance purposes. If it was intentional, there probably wouldn't have been be a crisis in the office. If it was not intentional, I'd say the computer went down. After it went down, I'd say that it was down.
failed We never used to say this.
was down See my comment above.
Best wishes, Clive