Had a call from somebody whose key had snapped off in the lock this week. I was expecting it to have happened when they had attempted to turn the key in the lock but this turned out not to be the case. The key had been left in the lock on a set of bi-fold door doors and when the doors had been opened the key had hit one of the other doors and snapped off in the lock. So it would seem that the key should always be removed once the door is unlocked. On another job the customer asked me to open the locks to an industrial unit to which the keys had been lost and afterwards paid the bill and kindly gave me a large quantity of laundry liquid and fabric conditioner from inside so at least my laundry will go down for a while whilst everything else goes up!