Internal relations in a crisis situation

Here is a real internal relations challenge - last year a DVLA worker joked as she opened a parcel that it could be a letter bomb.  This turned out to be the case and she and her colleagues were injured.  Colleagues have apparently refused to work with the woman blaming her for the incident.

Given that there had already been several instances of letter bombs being targeted at motoring organisations, one wonders if there hadn’t been any internal communications regarding what action to take if a suspicious parcel was received.  After all this was a crisis that should have been anticipated.

Obviously the person who sent the bomb is ultimately responsible, but to what extent does the organisation have culpability, or the unfortunate woman who opened the package?

And, how is the DVLA managing this post-crisis situation - can the sense of a lack of trust between colleagues ever be repaired?