You have read the How to Prepare section and are aware of your surroundings as well as what to do. When an emergency does happen, you need to act.
The Emergency Response Guide and the Emergency Response Guide for People with Disabilities can help you for the most common situations that can happen - become familiar with it to understand your work or study environment.
Keep an eye out for Security Services Personnel or any first responders (fire, police, emergency medical services) and obey their instructions.
Lockdown video coming soon