In many circles, tiptoeing around the truth is the norm. Public relations in a crisis shouldn't be one of those circles.
Good PR shouldn't be about how well you can sanitize the truth. It should be about how well you can tell the truth to build trust.
There are always other "considerations" — legal, logistical and hierarchal. However, the digital age puts a premium on rapid truth-telling, which should be considered as or more important than other factors in deciding what to say and when and where to say it.
Truth-telling implies having verifiable facts at hand. In a crisis, facts can be elusive. Explaining the urgency by which you are seeking facts is part of candid truth-telling. Meanwhile, you can demonstrate your engagement in the crisis in other ways, starting with a statement of remorse and actions to deal with the problem at hand.