What was that thing at 6600 west Grand ave?

Sorry ,didn’t edit the first thread in time~~~~~~~~~~~~~~~~~~~~~~~~~
First of all ,HELLO to all here. I am a newbie to SDC and a PROUD Chicagoan of over 51 years now.
My question pertains to the (long gone)structure that resembled an unfinished EL platform on Grand ave just west of Narragansett. I remembered reading something written about it in the papers back in the 70s. Possibly something to do with WW2. Can anyone share what they know on it? Thanks all

Could this be what you were referring to:


In case you miss it, page 2 of the thread in the above link has a picture of the thing.

That’s it exactly. Wow what nostalgia ! The info/link is appreciated my friend I had forgotten just how huge it was…
From one Dave to another thanks again~Artista