Weeks earlier, a plumbers' strike had hit the construction. There was not enough time left to finish both the restrooms and the drinking fountains.
Walt had to choose, and he chose the restrooms. People could buy a soft drink, he reasoned, but they could not relieve themselves in the street.
On a 100-degree day, that left almost nowhere to get a free drink of water. Anyone who was thirsty had to buy something.
Then that ran out too. Within hours, the restaurants and refreshment stands had sold through almost everything they had.