1.   They pass a stone doorway in the tunnel wall, but by-pass it in favour of a more obvious way out.

2.   An inscription on the tunnel wall, written in ancient Hebrew script, tells how two teams digging from opposite ends managed to meet in the middle.

3.   Exposure of the concrete to the sulfates became a hot issue for MTA officials when the plastic liner protecting the tunnel walls was found to be torn in places.

4.   Half a mile underground, hissing rubber air hoses were looped along tunnel walls and small lights hooked on the hard hats of miners bobbed in the inky universe.

5.   He turned a flashlight on the dark tunnel wall.

6.   Instead, he precisely fits together beams of dried wood to shore up his tunnel walls.

7.   That caused an electrical connection to a patch of metallic tunnel wall left exposed when workers failed to replace concrete after working in the area.

8.   The rest of his body was crouched in a seated position inside the tunnel wall, his head between his knees.

9.   City crews said the spigot could not be turned off until the fire was extinguished, hazardous materials had been removed and the tunnel walls had been certified safe.

10.   City crews said the leak could not be stopped until the fire was extinguished and the tunnel walls had been certified safe.