During a power outage in a large building, what is a security guard's most important immediate action, assuming emergency lighting is activated?

1. Check critical areas, assist with safe evacuation or shelter-in-place as per procedure, and report status.
2. Attempt to restore power to essential systems using backup generators.
3. Begin a floor-by-floor search for emergency lighting failures and reset breakers.
4. Instruct all occupants to remain calm and stay at their current location until power is restored.