The five levels of terrorism alerts outlined by the Department of Homeland Security, as well as recommended government and private-sector responses:
RED: Severe risk of terrorist attacks.
--Assign emergency response personnel and preposition specially trained teams.
--Monitor, redirect or constrain transportation systems.
--Close public and government facilities.
--Increase or redirect personnel to address critical emergency needs.
ORANGE: High risk of terrorist attacks.
--Coordinate necessary security efforts with armed forces or law enforcement agencies.
--Take additional precaution at public events.
--Prepare to work at an alternate site or with a dispersed work force.
--Restrict access to essential personnel only.
YELLOW: Elevated condition. Significant risk of terrorist attacks.
--Increase surveillance of critical locations.
--Coordinate emergency plans with nearby jurisdictions.
--Assess further refinement of protective measures within the context of the current threat information.
--Implement, as appropriate, contingency and emergency response plans.
BLUE: Guarded condition. General risk of terrorist attack.
--Check communications with designated emergency response or command locations.
--Review and update emergency response procedures.
--Provide the public with necessary information.
GREEN: Low risk of terrorist attacks.
--Refine and exercise planned protective measures.
--Ensure emergency personnel receive training.
--Assess facilities for vulnerabilities and take measures to reduce them.