Yes, they still have these kind of incidents quite often in Germany it seems, that one seemed to be a big one though.
Why they detonate it at night?
It was a 250 pound bomb with long time fuse that should be triggered by a glass ampoule with acetone. The bomb was found on Monday during construction work on the subway, a disarm was not possible, therefore they decided to blow it up.
Better safe then sorry.
What a coincidence – they found one on our airport (Schiphol) this morning as well They’ve moved it out of the capital for a controlled detonation too