Step 1: Recalling the Text:
In William O. Douglas's 'Deep Water', at around age ten or eleven, Douglas went to the YMCA pool in Yakima to learn swimming.
Step 2: The Incident:
A big boy, as a prank, suddenly picked Douglas up and threw him into the deep end of the pool. Douglas sank to the bottom, panicked, swallowed water repeatedly while trying to rise, and nearly drowned/lost consciousness before someone eventually rescued him. This terrifying near-death experience left him with an intense, long-lasting fear of water.
Final Answer:
As a boy of about ten, Douglas was thrown into the deep end of the YMCA pool by a bigger boy as a prank; he sank, panicked, swallowed water and nearly drowned before being rescued — this traumatic incident gave him a lasting, deep-rooted fear of water.