I've just been on a great one, thought I'd share:
"Customer has had a fire at their premises, suspects some comms equipment may have been affected, fibre link to switchboard is down"
OK thinks I, toddle off to the premises expecting maybe some part of the building has caught fire and smoke/water has got near the comms room, or power is out, etc...
No - the switchboard CAUSED the fire! The cable came out of the BT box and went into a pile of melted plastic and metal that used to be the switchboard.
Got the fibre link working again and told them all they need to do now is peel the switchboard off the floor and plug a new one in