Nuclear Incident

Improvised Nuclear Device (IND)

An improvised nuclear device (IND) is a small nuclear weapon that was created from illegally obtained equipment and materials. Despite their size, small nuclear weapons are far more destructive than chemical weapons like TNT. An improvised nuclear device can have the same destructive force as 10,000 tons of TNT and would do catastrophic damage if it exploded in New York City. A nuclear explosion could destroy many buildings within a half mile from where it exploded.

Nuclear Explosions

The first sign of a nuclear detonation will be the intense, blinding flash of light that can be seen from miles away. Even if facing away, the light from the explosion reflected from nearby objects may be bright enough to cause temporary blindness. Depending on how far away you are from the nuclear explosion, known as ground zero, it may take several seconds before the sound of the blast can be heard. The boom may sound more like a gunshot than a thunderclap and will be followed by a sustained roaring sound.

Improvised nuclear devices may produce a mushroom cloud rising from ground zero. That cloud contains dangerous, radioactive particles called “fallout.”

Fallout will look like small, sandy particles falling from the sky. It can fall to the ground soon after the explosion. You must avoid it by seeking shelter. Exposure to fallout that is falling or has just fallen may be fatal.

Health Risks and Hazards

A nuclear explosion creates a lot of hazards. It can:

  • Start fires
  • Topple buildings, overturn automobiles and cause structural damage over one mile from the explosion
  • Break building window glass further than three miles away
  • Damage electronic devices including computers, radios, televisions and medical equipment
  • Cause severe injuries due to flying debris at least one mile from the explosion
  • Cause fallout that can lead to radiation sickness that may be fatal

Health Risks of Radiation Exposure

A nuclear explosion and fallout from it can produce large amounts of radiation. You can get acute radiation sickness if you are exposed to a large enough amount of radiation. This painful condition can be fatal. Symptoms of radiation sickness include vomiting and diarrhea. Exposure to radiation can increase your chances of getting cancer.

Breathing in radioactive materials could increase your exposure to radiation. An open wound is another way that radioactive materials on your skin can enter your body and result in longer exposure to radiation.

To reduce your exposure to radiation and the chance of getting radiation sickness, go inside immediately after the explosion. Stay there until authorities say it is safe to evacuate.

Radiation and Pregnancy

The effects of radiation depend on the radiation dose received and the trimester of the pregnancy. A fetus in the early stages of development (two to 18 weeks) is more vulnerable to a high level of radiation than later in the pregnancy. Pregnant people who were exposed to fallout, particularly on the face and head, should remove and bag their clothing, and then shower and shampoo as soon as possible.

Protect Yourself and Others

You and your family should get inside, stay inside and stay tuned for information from authorities. Expect to shelter indoors for at least 24 hours. Authorities will notify you when it is safe to evacuate. If you were outside when fallout was falling or had just fallen, take off your shoes just after entering the building to avoid spreading contamination.

If you know or think you have fallout on your hair, skin, or clothes:

  • Brush it off with gloves, rags or a broom.
  • Wash your hands, neck, face and hair, or take a shower if you can. Wash your hair well, but do not use hair conditioner, including 2-in-1 hair shampoo and conditioner. Conditioner can make fallout particles difficult to remove.
  • If it is not possible to shower, you can use wet wipes (such as baby wipes) or water from a container to clean your hands, face, and especially the areas around your mouth, nose and eyes. Discard the wipes with contaminated clothing. Place them in sealed trash bags. Do not place them with your dirty laundry.

Safely Seeking Shelter Indoors

You should try to seek shelter in a building’s basement. If the basement is unavailable, seek shelter in the center of the building away from walls and windows. Shut any doors and windows.

Stay away from parts of the home or building near the roof, fire escapes and balconies where fallout can collect. Do not shelter in your car.

Protecting Your Pets

Wash and dry off your pets if they were outside when fallout is present. Keep them indoors. Do not shave your pet’s fur as an alternative to washing. Shaving will not get rid you of the radioactive fallout particles.

Food and Water Safety

Avoid food located outdoors because fallout can settle anywhere that is open to the air. Fallout will not contaminate food stored in your home. You can eat food such as canned goods, food stored in the refrigerator or freezer, boxed foods and food in bottles or jars. If you’re unsure, rinse food containers before opening them. You can also rinse plates, glasses and silverware before use.

It is safe to eat peeled fruits such bananas and oranges. You should rinse fruits and vegetables that are not peeled before eating.

Drink bottled water until public health authorities say that tap water is safe. Drinks in cans, bottles, juice boxes, cartons or other sealed containers will be safe to drink. Boiling tap water will not remove radioactive contamination.

Staying Tuned in for Information from Authorities

If you have electricity and a television or radio, turn it on and tune in to get information from authorities.

If the power is off, you may need a battery or crank-operated portable radio. You should consider purchasing this type of radio in advance so that you are prepared.

Cell phones and computers may not work due to the effects of the explosion. Try powering them off and back on.

Detect and Treat Radiation Exposure

Radiation triage and treatment centers will be set up where people can receive a medical screening for radiation exposure. These centers may not be operational until three or four days after the explosion. The locations of these centers will be announced by government authorities.

Treatment for Radiation Exposure

There is no over-the-counter treatment for radiation exposure. The radiation from a nuclear explosion and from fallout can penetrate the body and all internal organs. The best protection is getting indoors and staying inside until authorities provide further instructions.

Evacuation and Returning Home

In the first few days after a nuclear explosion, the safest place to be is indoors. You will get less radiation exposure if you stay inside.

You may also face many hazards trying to self-evacuate. The explosion may damage electrical power lines, communications, roadways and mass transit. The worst damage will be closest to the detonation site, but even mass transit far from the explosion might not be able to run. Car travel will either be very dangerous or impossible, due to vehicle collisions and rubble blocking roadways. You may also encounter fires, downed power lines and ruptured gas lines outdoors.

At a safe indoor location, tune into a radio, television or other electronic device such as a smartphone, tablet or computer to stay updated on instructions from authorities. A portable battery-powered or crank-operated radio is helpful in case there is a disruption to electricity. Tune into 880 AM or 1010 AM for emergency notifications.

If you must evacuate, authorities will notify you when it is safe to do so.

Reuniting with Children and Other Family Members

Do not pick up your children from school or daycare. Schools and day care centers have emergency plans and know how to keep children safe. Going outside in the first few hours after a nuclear explosion could expose you to a fatal dose of radiation or other hazards. Stay indoors until authorities provide instructions.

Evacuation Instructions

Authorities will determine and instruct the public about the safest evacuation route. Follow evacuation instructions because they are designed to keep your exposure to radiation as low as possible and to avoid other hazards outdoors.

Authorities may share this information in many ways, including by television, radio, smart phone and the internet.

What to Bring When Evacuating

New York City Emergency Management has put together a list of recommended items to keep in your Go Bag. Radioactive fallout particles are usually too large to breathe in, but there may be other harmful particles in the air from collapsed buildings, fires and other damage. Wear a mask if you have one, but you don’t need a mask to evacuate. If you don’t have a mask, use handkerchiefs or other articles of clothing to cover your nose and mouth. If you have pets, you can bring them with you when you evacuate.

Returning Home

A nuclear explosion will cause a lot of damage to the city. It will be very difficult to predict if or when you will be able to return home. Whether you can return home will depend on its location. Even if your home is far away from ground zero and does not have a lot of damage, radioactive fallout may still contaminate your neighborhood. The levels of radiation in your neighborhood could last for years before decreasing to a level considered safe to return home. It will also take a long time for the city to repair power, water, communications, roadways and public transportation services needed for people to live in the city long term.

Preparing for a Nuclear Attack

The thought of a nuclear terrorist attack is very stressful. An IND explosion in or near NYC would be very dangerous and cause great loss of life. But, despite the terrible damage, there would be many survivors. By following the information on this page and taking quick protective action, you will increase your chances of survival. The most important actions to take are to get inside, stay inside and stay tuned.

There may be warning of a possible nuclear attack about to happen, particularly during times of global conflict. During these times, you should stay informed and follow instructions from government authorities.

After an IND explosion, the government will send out information and instructions over radio, television, phone, and internet. Possessing a portable radio (crank or battery operated) is an excellent backup to smart phones, and other devices that are dependent on the Internet.

Visit the NYC Emergency Management website to learn more about what to do, how to find loved ones after an emergency, and how to communicate during an emergency.

Sign up for emergency notifications at Notify NYC.

You make a go-bag by following these instructions at

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