Duck and cover revisited
Oh, come on now, just because the alert sent the populace running for futile shelter doesn't mean that it wasn't really a good time for all! This is the perfect thing for a BOFH to spring on a boss.
Seriously, by the time an alert like this goes out, the people will only have a few minutes to find shelter. It only takes 12 minutes from North Korea to Hawaii. You can bet that most shelter won't be adequate.