All available information, as long as it does not involve some security or confidential issue, should be made public. People may very well find out anyway through another source. Cover all bases and all the important subjects. If information on a particular area is not released in detail, questions will focus on that area and make it seem far more crucial than it may be. Realize the fewer people who know what is going on, the more the public fears the possible consequences.
Crises can yield positive results, if they are handled appropriately.
For example, an organization can improve its media relations, its reputation as a resource to the community, its credibility, its employees' morale and its clarity of focus and roles.