He described the things I have attempted to describe before-the fortified streets and houses of Lens, which make it one great fortress, tunnelled from end to end with exits into concrete forts two yards thick in cement, in the ruined cottages.
"From Bapaume to Passchendaele, 1917"
Philip Gibbs
At first he could not understand, for he was certain that both exits were closed, and the tube itself was air-tight.
"The Gray Phantom's Return"
Herman Landon
Then he made his way to one of the exits and disappeared.
"The Way of Ambition"
Robert Hichens