Felix 9 would be in an advantageous vantage point with a very high powered sniper rifle, concealed in a fake HVAC housing, following the activities through the optics waiting for the mask to fall.
Thunderbird, and the rest of his team would be observing, He would probably be at a fairly high altitude, with his team mates on the ground, in various locations, reporting in. Again, waiting for the subjects to do something criminal. If nothing criminal is done, they will observe them leaving, and then stand down, change into civilian clothes, meet in the back room of a Denny's, and discuss what was observed.
Sgt. S.M.A.S.H. {robably watching the parade on Television. He himself is unfamiliar with C.L.O.W.N.