Blackouts can assume existence-threatening proportions due to the interconnected systems in large companies. In this book, a blackout is derived as a total power failure in large parts of the country and beyond its borders, which can last from several hours to several days.In the event of a blackout, companies will convene their crisis teams to avert major damage and return to normal operations as quickly as possible. In order for crisis teams to be able to make the right decisions, the primary prerequisite is the ability to act and thus the alerting and supply of participants, which is not ensured in the event of a blackout due to communication failures. Furthermore, up-to-date situation reports from the affected regions are essential for the ability of crisis teams to make decisions, but these are also dependent on the continuous availability of communications. Especially for state-owned railroad infrastructure companies, a network-wide power blackout, in which thousands of passengers could be stranded and have to be informed, would be fatal.