I came in to work to find one of our buildings off the network. After the usual checks I ventured out to investigate with laptop, socket testers and cable testers. The switch seemed to be up but no link back to the nearest hub. As we do not have diverse routes into this building it was one fibre that was the problem. I went to the other end and tested it, all working at that end.
Then I noticed the hole in the road...
Apparently, the night before, an electricity cable had gone 'pop' and melted through all the ducts... and our fibre cable.
Here is what is left of our fibre:
...and here is the electricity cable:
I'm glad I wasn't walking down the street at the time.