One small example from right at the very end is the October 1989 refugee trains, which left the West German embassies in Prague and Warsaw after their respective agreements. They were locked as they passed through East Germany, and conditions depended on which train you took, but there were at least a few thousand who escaped in this last month before the Wall fell (of course, they didn't know it was coming), just as the (earlier) Monday demonstrations were taking place simultaneously in German cities. See the NY Times archived article from the 6th of October: http://www.nytimes.com/1989/10/06/world/jubilant-east-germans-cross-to-west-in-sealed-trains.html