Yeah, I'd call them. On TV, they said the tornado was going 50 mph Falls Church - Arlington - Alexandria.
Glad I took your advice. They're OK, but they said they heard on the radio that a tornado may have hit the Mantua neighborhood. That's right near where they live—I walked to school at Mantua via a path through the woods when I was in fifth and sixth grade in the early 1980s. (Now they have a bus, paths through woods apparently considered unsafe for kids....)
