Sandbagging In San Francisco, Philippine Clipper Arrival

The video covers various wartime efforts, starting with London's sandbagging for defense. It highlights the safeguarding of the Pacific Telephone and Telegraph Company building as a crucial communication hub. In San Francisco, the Philippine Clipper receives war paint after a heroic mission, where the crew witnessed the bombing of Wake Island and rescued Pan American Airways personnel.

What does the term 'sandbagging for defence' refer to in the context of the text?

Who were rescued by the crew mentioned in the text?