They couldnt let more people through due to fire codes. if the train aint moving there is only so many people who can stand in the tram area. thus they shut down the security check point.

They didnt build an alternate walking path to the trams because DIA was way over budget. thus when this happens you are SOL.

This was talked about on another thread with the stoppage.

What I am not sure if this was independent of the Hotel construction or because of it. they are building an airport hotel right next to the airport.