If a nuclear bomb explodes, government officials will probably use these scripts to calm you down
But none match the specter of a nuclear explosion.
A small nuclear weapon on the ground can create a stadium-size fireball, unleash a city-crippling blastwave, and sprinkle radioactive fallout hundreds of miles away.
The good news is that the Cold War is over and a limited nuclear strike or a terrorist attack can be survivable (a direct hit notwithstanding). The bad news: A new arms race is likely underway - and one that may add small, portable nuclear weapons to the global stockpile. Lawmakers and experts fear such "tactical" or battlefield-ready devices (and their parts) may be easier for terrorists to obtain via theft or sale.
"Terrorist use of an actual nuclear bomb is a low-probability event - but the immensity of the consequences means that even a small chance is enough to justify an intensive effort to reduce the risk," the Bulletin of the Atomic Scientists said in a September 2017 article, which outlines what might happen after terrorists detonate a crude device that yields a 10-kiloton, near-Hiroshima-size explosion in a city.
A nuclear terrorist attack of this magnitude is one of 15 major disaster scenarios planned for by FEMA and other US agencies. (The same scenario also includes a dirty bomb explosion, though such an event would be dramatically less harmful.)
As part of the planning effort, the Environmental Protection Agency maintains a series of manuals about how state and local governments should respond. A companion document anticipates 99 likely questions during a radiation emergency - and scripted messages that officials can copy or adapt.
"Ideally, these messages never will be needed," the EPA says in its messaging document. "[N]evertheless, we have a responsibility to be prepared to empower the public by effectively communicating how people can protect themselves and their families in the event of a radiological or nuclear emergency."
Here are a handful of the questions the EPA anticipates in the event of a nuclear emergency, parts of statements you might hear or see in response, and why officials would say them.