Can attest that we here in Northern VA have no sirens. Saw some funnel clouds forming on the way home a couple of years ago and knew what that meant. Drove like the dickens (violated several speed laws by at least a factor of two to three).
Got home and one tornado hit while we were still getting into the house. We could barely move but somehow made it inside. Were running to the door to the basement when it hit with full force. Everything became pitch black.
We were pretty lucky. It cost us a heck of a lot of money, the things that were destroyed, mainly very large trees, the insureance would not cover.
But we and most of the house came out OK. Thank goodness.
Some neighbors did not fare anywhere near as well. No one, thank God, was hurt. But we all pulled together and the neighborhood is back to its old boring self.
Can only say take tornado warnings very seriously.
This whole thing happened in a heart beat, in an area that essentially never has tornados.
Lived in tornado country and never saw one although the sirens would go off every so often.
And go figure, were hit in the head by one in a place they just don't usually show up.