He put action to words and a small panel slid open to one side of the main door.

A panel in front of him slid to the side.

The panel slid back, and then another, larger opening came as before.

The girl touched the wall, and a panel slid away.

A much larger panel below slid into the wall, and left an opening big enough for the children to pass through.

The panel on the east wall slid open silently, and he walked through.

A panel in the back of the closet was slowly sliding open.

As it did so, a panel in the wall slid silently open.

At the same time, five panels slid silently open, one after the other.

They all looked to the door of the bunker as the panel slid open.