The difference between Shelter-In-Place and Lockdown

  • Published
  • By Senior Airman Alex Sheridan, Hill AFB Readiness & Emergency Management Flight

HILL AIR FORCE BASE, Utah -- Knowing the difference between shelter-in-place (SIP) and lockdown could save your life. Most military personnel know the difference, but what if you’re a civilian who lives or works on a military installation? Have you been educated on the differences between SIP and lockdown?




The SIP program enables personnel to protect themselves from airborne hazardous materials during a chemical, biological, radiological, or nuclear (CBRN) incident. When the installation commander advises SIP, personnel will go to the designated SIP rooms in each building to initiate SIP procedures.


The first person to arrive in the SIP room will grab the SIP checklist from the SIP kit and start reading it out loud. One person should go turn off the HVAC systems. Another person should go lock the doors leading to the outside and put up SIP in-progress signs so that personnel trying to enter or leave won’t open the doors. Once those individuals return to the SIP room, everyone but the one reading the checklist should be grabbing the pre-cut plastic and taping it to the doors and windows. Vents shouldn’t be covered unless the HVAC system won’t turn off. After the doors and windows are sealed off, personnel will take accountability to make sure they know where everyone is located. Once accountability occurs, personnel will wait in the SIP room until SIP is lifted. Once SIP is lifted, personnel will pull down the plastic, turn the HVAC systems back on, and open all windows and doors to air out the facility.




Now that you’re aware of SIP procedures, you may be wondering what the procedures are for lockdown. In the event of an active shooter incident, the installation ‘Giant Voice’ will announce three times, “LOCKDOWN, LOCKDOWN, LOCKDOWN, the last known threat area is (affected area).” The installation mass communication system will be used to alert personnel of an active shooter incident. The sound of gunfire may be the only notification you receive … if you hear it, ACT.


The three most important things to remember are: run, hide, and fight (if necessary).




  • Evacuate to safety; if there is a way out, take it. Be sure to have an escape route and plan in mind.
  • You should evacuate regardless of whether others agree to follow.
  • Leave your belongings behind and attempt to help others escape, if possible.
  • Once you are out of the danger area, prevent other individuals from entering an area where the active shooter may be.
  • From a safe location, call 911. Notify the dispatcher of the building number where the active shooter is located, as well as numbers, locations, physical descriptions, and types of weapons used by the active shooter, if known. If possible, give an approximate number of victims.
  • Once law enforcement arrives, keep your hands visible at all times and follow instructions from police officers. Don’t stop to move wounded people. 



  • If evacuation is not possible, find a place to hide where the active shooter is less likely to find you.
  • The hiding place should be out of the active shooter’s view and, if possible, provide protection from shots fired in your direction.
  • If you are trapped in your office, lock and barricade the door, and take cover.
  • If the door does not lock, blockade the door with heavy furniture.
  • Turn off the lights, silence your cell phone and/or pager, and turn off any source of noise (e.g., radios, televisions).
  • Hide behind large/heavy items (e.g., cabinets, desks) and remain quiet.
  • Stay clear of window and doors. 



  • Be prepared to defend yourself if all other means have failed.
  • As a last resort, if your life is at risk, whether you are alone or working together as a group, fight!
  • Act as aggressively as possible by yelling and using whatever weapons can be fashioned from the immediate surroundings (e.g., chairs, keyboards, 3-hole punches, etc).
  • Fully commit to your actions until the shooter has been completely incapacitated and disarmed. 

Personnel outside the immediate area where the shooter is located will:


  • Find the nearest cover and stay there. Stay vigilant for potential threats. Move to a safe location away from the threat area when you receive further updates from mass communication systems.
  • Follow directions given by identified law enforcement personnel or by mass notification systems. Evacuation may be directed by building or one room at a time.
  • Secure facility exterior doors if it doesn’t jeopardize the safety of personnel. 

Actions personnel should take when encountering Security Forces or other law enforcement personnel:


  • Remain calm and follow instructions.
  • Place items that are in your hands on the ground.
  • Raise your hands and spread your fingers.
  • Keep hands visible at all times.
  • Do not make any quick movements toward Security Forces personnel.
  • Provide any information that may assist Security Forces in countering the threat.
  • Avoid pointing, screaming, and/or yelling.
  • Do not grab Security Forces members or make any quick movements toward them. Allow them to pass by, because they are trying to get to and neutralize the shooter.
  • Move quickly to the assembly point. Expect to stay there until the situation is under control and all personnel have been identified and questioned. Don’t leave the assembly point until instructed by Security Forces personnel.

Security Forces’ purpose is to neutralize the shooter as soon as possible. Responding

Security Forces members will proceed directly to the area where the shots were heard.


SIP involves temporarily sheltering from airborne CBRN hazards as opposed to lockdown, which involves running, hiding, or fighting during an active shooter incident. For more information on SIP, call the Readiness & Emergency Management Flight at 801-777-4910. For more information on lockdown, call the Installation Antiterrorism Manager at 801-777-1868.