Here are some pics of a recent opening I had to witness. It was not done by a locksmith, but rather the fire department that is traditionally responsible for opening doors in cases of emergency here in Germany. Might still be of interest to you guys.
The problem was the additional locks, the Abus bolt lock. A key to the normal lock was available, but no key to the Abus lock.
There was an attempt to pull the plug on the cylinder of the bolt lock first, but the screw broke and the cylinder was bent badly during this.
As they could not get a second screw in it was decided to cut the door in half. This is the outcome, now repaired for the time being by stabilizing it with two wood boards.
They were using a hell of a mean saw. It went through the plate on the inside with hardly noticing any resistance.
Reason they did not have to through the entire process and break the door in half was that the extreme vibration of the saw transferred to the door, the wall mount of the bolt lock gave way. So, essentially the door could be opened in one piece, with the bolt lock still extended. On this pic the bolt is retracted now, though.

Due to financial limitations the light at the end of tunnel has been turned off until further notice.