USA TODAY Sports
The second day of the Rio Olympics saw some of the best American athletes take center stage. Michael Phelps, Katie Ledecky and Simone Biles all competed, though for different stakes. Here's what you might have missed:
Pool party!
That's more or less what the Americans threw Sunday night in Rio. Katie Ledecky obliterated her own world record in the women's 400-meter freestyle. The 19-year-old beat her previous record by almost two seconds. She's the world-record holder in the 400, 800 and 1,500 freestyle events.