He looked out across the bridge to the catwalk and the airtight door that led to safety.

There was a small, airtight door at the end of the tunnel.

At the far end were shelves and another oval airtight door.

They went through another airtight door, which Tad closed behind them.

We've got most of the place stopped off with the airtight doors.

We've shut all the airtight doors, but we're still losing atmosphere.

Get boys in from tunnels and close all airtight doors!

There's a control panel set into the wall next to each of the airtight doors.

After agreements all around, they opened the airtight door and entered the environmental control center.

Once on board he found himself in a narrow corridor with an airtight door at the far end.