. >> reporter: super-broker mary ann tighe is ny c.e.o.f the world's largest real estate services firm. >> yay! we can all get each other on the screen, but it doesn't tell us a darn thing about real life work from home. >> reporter: have there been no fire sales of office buildings from landlords who need the cash? >> there have been no fire sales to date, this is not a moment where you want to place a valuation on an asset simply because you may get an answer you're not going to like. and the answer may be different a month from now or six months from now. >> reporter: take blackrock, cbs's iconic manhattan headquarters, which tighe's firm had been preparing to sell for over a billion dollars. it's now off the market. why? >> i think people are on pause waiting to see what the market reveals. >> reporter: bob edelstein, however, has evidence that uncertainty is actually killing real estate deals at the moment. >> i'm privy to 10 recent potential transactions. six have stopped negotiating. i don't know if they'll ever negotiate again. thr