The Good Wife Star Rushed to The Hospital After Injury On The Set

A source connected to the production of the CBS show tells us ... Kristin was struck by a piece of lighting equipment and fell to the ground.

We're told Kristin smacked her head on the concrete during the fall ... and required medical attention.

Someone on the set called 911 around 5:07 PM ET to report a woman who had been hit in the head by a scaffold.

TMZ spoke with a witness who was on the scene who says, "That area is a vortex for wind ... and a big gust of wind blew the lighting off the scaffolding."

The witness tells us Chenoweth was hit "square in the head" and appeared to be "knocked out cold." The witness says, "I thought she was dead at first."

Kristin was taken away from the set in an FDNY ambulance (pictured above) and was admitted to a nearby hospital.

A rep for the New York Fire Dept. tells us ... the victim is being treated for "minor injuries" connected to the accident.

Kristin seems to be accident prone ... she injured her neck during the pre-Broadway engagement of "Wicked" in 2003.

Then, in 2006 she fell off an elevated section of the stage during a rehearsal of the Broadway revival "The Apple Tree."