I wish to bring a discussion on the Ending that is played when the player escapes from Gate A.
To explain, after the player runs down to the tunnel beneath the bridge, the player moves down the tunnel only to be trapped by three unknown individuals (Wearing military clothing) and they tell you that "You know too much to let them kill you, you're coming with us!".
I have the theory that they are members of the Chaos Insurgency and have captured you because of everything you have learned about the site and the located SCP's. Also their vague appearance is the same as the ones that appear occasionally on the info screens during the load screens (Also the MTF members).
Gate A "Spoilers"
#1SCP:CB Administrator. 99% of my statements are my own and do not represent the official developers viewpoint.