Here in high tech-land Germany an excavator did cut the cable that provided our allegedly 700MBit Internet.
I could have a look in it's construction: a post-WW2 cable with tar-paper isolated copper wires !
The repaired the damage and we still use this museum-ripe cable...for 2014's Internet.
This is just my speculation, but perhaps what you saw was just the metal cover and extra protection for the very thin fiber cable at the very center of it. Or maybe those are multi-purpose cables, and the metal wires serve some other purposes as well.