For the first time in major league history, five grand slams are hit in a single day. Cardinal Fernando Tatis, Expo Jose Vidro, Marlin Mike Lowell, Yankee Bernie Williams, and Mariner Jay Buhner all connect to set the record. (Lowell, Williams, and Buhner all played for the Columbus Clippers – thanks to Steve Basford for this interesting aside.)

On August 9, 1999 — For the first time in major league history, five grand slams are hit in a single day. Cardinal Fernando Tatis, Expo Jose Vidro, Marlin Mike Lowell, Yankee Bernie Williams, and Mariner Jay Buhner all connect to set the record. Lowell, Williams, and Buhner all played for the Columbus Clippers.