It turned out to be a false alarm, but it got me thinking about what I would do if I received this alarm now. Something like:

1. Bring my kids down to the basement. Tell them we're going to need to stay there for a while.

2. Get the kids settled, probably watching a video on a tablet. They don't get to do much of this (generally ~3min/day) so it would probably be enough to keep them distracted.

3. Go back upstairs and grab blankets and pillows. Air mattresses too if there seems to be time. These aren't things it makes sense to keep in the basement because they might get moldy.

4. Turn on the radio. We have a hand-crank one in the basement if the power's out.

5. If it seems like there's time, close upstairs windows.

6. Seal the openings to the basement (windows and doors) with plastic sheeting and duct tape.

7. Wait, hope it's a false alarm.

8. If it's not a false alarm, and we survive, take potassium iodide tablets.

9. After a while, remove the window sealing and get the place ventilated.

10. Stay in the basement for two weeks. Not fun.

Maybe I should read Nuclear War Survival Skills, or at least keep a copy in the basement. Things that are already in the basement that would be helpful are food, water, potassium iodide tablets, hand-crank radio, some other things.