Hm. I distinctly remember that number from a talk but I can't find a reference. The closest I found is this: http://www.lifesaving.com/issues/articles/13swimmi

Hm. I distinctly remember that number from a talk but I can't find a reference. The closest I found is this: http://www.lifesaving.com/issues/articles/13swimming_pool_drownings.html http://www.lifesaving.com/issues/articles/13swimming_pool_dr... .. which has the high number but is hard to interpret and doesn't cite its own sources. It does sound surprisingly high, though, I'll change my comment to "thousands", which I hope you'll agree is "safe".