Safety and security are always top concerns at an event, and it often falls on the shoulders of planners to have appropriate measures in place to manage risks in these categories. Even at events where these services are outsourced, the lead planner must be aware of who is covering the bases. This is because, at the end of the day, attendees are going to look to the event professional for guidance during an emergency.
Like so many other facets of event planning, half the battle is communicating safety needs and procedures to everyone involved with the event. Planners should be the "know all" source for safety and security, but the best way to keep everyone safe is to disperse information through to everyone else on the staff.
There are several strategies you can use to prevent chaos in an emergency situation. I've outlined what I feel are the most important ones in this article: 5 Essential Safety Measures for Event Planners.