Is This Lawful?

My question involves towing laws for the State of: Virginia.

I parked my car at the shipyard where i normally park it on the side of the street this morning around 4 AM and went back to the barracks to sleep a little before work began today. While I was at work they built a sign saying that it's a tow zone although this is the first time that they made this known. Along with a lot of other cars that parked on the same side of the street, I got towed. The question I would like to ask is if that is legal for them to immediately tow us like they did. We had no prior knowledge of this sign and they never notified us that it was going to be put up. I'm quite sure that if we were told so, then no one would have parked in that particular area. Can you please give me feedback on what the best solution to this would be?

Was it a tow zone? Was it posted as a tow zone? Who towed you?

If it was a tow zone, they did not put any signs showing that it was prior to uthem building the sign after everyone parked there. I park there very often and so do others, but no one has gotten towed until the sign was recently built. The towing company is called 7 city towing and the city had them tow all of us.

So they didn't put up a sign, except for the sign they put up? You're telling us, then, that it was posted as a tow zone prior to (and on) the day you were towed?