You don’t want your statement to become the victim of rumour in which the information is distorted and exaggerated. Providing long reports and complicated updates increases the possibility of people mis-communicating and exaggerating information.
Keep messages simple, and state the facts along with the actions you’re taking to rectify the situation. If possible try to give realistic timescales for recovery, or when you’ll be able to resume deliveries. Overestimating the length of this time is better than having to keep pushing back deadlines, which annoys and worries people who depend on your organisation.