""""A closed Delta Airspace towered airport is still a Delta Airspace
towered
airport. Closing the airport for whatever reason during the time the
tower
is open and the Class D surface area is in effect does not change the
airspace in any way.""""

I cannot tell if you are talking about closing the airport, or closing
the tower. If you are talking about closing the tower (airport stays
open), then you are wrong.

In order to enter "Class D" airspace, you need two way radio
communications. How would you satisfy this requirement if the tower
was closed? Talk to the line guys at the FBO? No. If you notice on a
VFR Sectional Chart, the class D airspace is usually also surrounded by
a fading magenta ring, indicating Class E down to 700' AGL. There
should also be a note near the Class D airspace that says "See
NOTAMS/Directory for Class D eff hrs," meaning the airspace closes when
the tower closes. The NOTAMS/Directory will tell you what time this
happens.

This is much more common than you may think. It happens with some
Class C airspace as well. Chattanooga, TN is one example that I can
think of.

-Tim