In a crisis, communication supports action before it supports reputation. Protect people, contain harm, establish decision authority, and share verified facts quickly enough to be useful. State what happened, who or what is affected, what people should do now, what is being investigated, and when the next update will come.
Speed does not justify speculation. Use one source of truth, time-stamp updates, correct errors visibly, and adapt detail for employees, customers, partners, regulators, and responders. Acknowledge impact with humanity. After stabilization, explain cause and prevention only when evidence supports the claims.