1.   One way to prevent that is to install airtight doors.

2.   There were the guards who crammed the victims into the gas chambers and screwed the airtight doors shut behind them.

3.   He had a telephone, modem-equipped computer, television, video-cassette recorder, exercise bike and around-the-clock monitoring by colleagues just outside the airtight door.

4.   It is sealed on two sides by reinforced airtight doors and contains several small offices built round the central control area.