Get out when ready, then call 911 from outside

When your fire alarm sounds, your first action is to leave the building right away. Do not stop to gather belongings, check on the fire, or investigate the noise. Treat every alarm as a real emergency—even if you think it might be a false alarm or a test, you cannot know that from inside.

Once you are outside and at a safe distance from the building (at least across the street), call 911. Tell them your address and that your fire alarm has activated. Do not go back inside for any reason while waiting for firefighters to arrive.

If you live in an apartment or multi-unit building, alert your neighbors as you leave by knocking on doors or shouting a warning. Do not use the elevator—use the stairs only.

Key Takeaways

  • Leave your home or building when ready when the alarm sounds, without stopping to gather items or investigate.
  • Go to a safe location outside and across the street, then call 911 from there.
  • Never re-enter the building while the alarm is sounding or until firefighters have cleared it.
  • In an apartment building, warn neighbors on your way out by knocking or shouting, and use stairs instead of elevators.
  • If you cannot leave due to mobility issues or being trapped, move to a room with a door you can close and call 911 with your location.

If you cannot leave your home

If you are physically unable to leave—because of mobility limitations, being trapped by fire or smoke, or caring for someone who cannot move—do not try to force your way out. Instead, move to a room with a door you can close and lock, preferably one with a window. Call 911 when ready and tell them your exact location in the building, including the room number and which side of the building you are on.

Close the door behind you and seal gaps under the door with wet towels or clothing to keep smoke out. Open a window slightly to signal your location to firefighters and to get fresh air. Stay on the line with 911 until help arrives.

What happens after you evacuate

Once firefighters arrive, they will enter the building to search for the source of the alarm and check for fire. Do not approach them or re-enter until they tell you it is safe. They may need to ventilate the building, which can take 15 minutes to an hour depending on what triggered the alarm.

If the alarm was caused by cooking smoke, burnt food, or steam from a shower, firefighters will clear the building and you can return once they give permission. If they find an actual fire or cannot determine the cause, they will direct you to stay out while they investigate further.

Why your alarm went off (and what it means)

Smoke detectors trigger for several reasons. Cooking smoke, especially from broiling or frying, is the most common cause of false alarms in homes. Steam from a shower, bathroom fan use, or a malfunctioning detector can also set it off. Dust buildup inside the detector or a low battery can cause false alarms too.

Less commonly, the alarm is detecting actual smoke from a small fire—perhaps in the walls, attic, or a hidden space. This is why you must always treat the alarm as real and evacuate. You cannot tell the difference from inside the building, and the cost of being wrong is far higher than the inconvenience of a false alarm.

Preventing false alarms in your home

To reduce false alarms from cooking, keep your kitchen door closed while cooking and turn on the exhaust fan before you start. If you know cooking will produce heavy smoke, you can temporarily relocate the detector to another room—but only if you move it back when ready after cooking. Never disable or remove the battery from a detector to stop it from alarming during cooking.

Keep detectors at least 10 feet away from bathrooms and showers if possible, since steam can trigger them. Clean the detector every few months by gently vacuuming the outside vents with a brush attachment. Replace the battery once a year (many people do this when clocks change for daylight saving time, making it straightforward to remember).

If a detector keeps alarming for no clear reason, it may be faulty. Replace it with a new one rather than disabling it. A detector that cries wolf too often can lead you to ignore a real alarm.

What to tell firefighters when they arrive

When firefighters reach you outside, tell them where you were when the alarm sounded and whether you saw, smelled, or heard anything unusual before it went off. Let them know if anyone is still inside the building. If you have a medical condition that made evacuation difficult, mention that so they know to check for people who may not have left.

If you rent, you may want to contact your landlord or building management after firefighters clear the building, especially if the alarm was triggered by a building system issue rather than something in your unit.

Frequently Asked Questions

Should I call 911 if I think it's a false alarm?

Yes. Call 911 after you have left the building. You cannot know from inside whether the alarm is detecting real smoke or a false trigger, and firefighters need to check. It is better to have them respond to a false alarm than to ignore a real fire.

What if the alarm goes off in the middle of the night?

Leave when ready, even if you are groggy or confused. Get outside and call 911. If you live with others, wake them as you leave by shouting or knocking on bedroom doors, but do not wait for them—everyone should evacuate at the same time. Meet at a designated spot outside so you can account for everyone.

Can I go back inside to get my pet?

No. Once you are outside, do not re-enter for any reason, including to retrieve pets. Tell firefighters that animals are inside when they arrive, and they will search for them. Your safety comes first, and firefighters are trained and equipped to handle animal rescues.

What if my smoke detector keeps going off when I cook?

Close the kitchen door, use the exhaust fan, and keep the detector at least 10 feet from the stove if possible. If it still alarms frequently, move it temporarily during cooking—but move it back when ready after. If it alarms with no smoke present, replace the battery or the entire detector. Never disable it permanently.

Do I need to do anything special if I live in an apartment?

Use the stairs, not the elevator. Warn neighbors as you leave. Once outside, go to your building's designated assembly point if one exists, or across the street. Do not re-enter until firefighters or building management say it is safe. If the alarm was caused by something in a neighbor's unit, management may need to contact them.