On a school trip to the London swimming pool, Carl Powers died in what appeared in be a freak accident. It was only later discovered by Sherlock Holmes that Carl had his eczema medicine poisoned by Jim Moriarty.
When consulting detective Sherlock Holmes found the Bruce-Partington Plans, he arranged a meeting at the pool. There he encountered John Watson with a bomb strapped to his chest and his nemesis Jim Moriarty. After a standoff, Jim was called by Irene Adler and he departed the pool.
The London swimming pool appeared in the Sherlock episodes: