In SF during the summers of 1944 and 45, kids were told to stay away from community pools. Polio epidemics in the Bay Area and in other parts of the country were striking down and crippling many hundreds of kids 16 and younger. This highly contagious viral disease was believed to be spread in public places such as pools. Playgrounds were included, and some were closed in July and August. It would be years before the Salk vaccine was developed.