The final of the Men's 400 metres Hurdles event at the 2003 Pan American Games took place on Wednesday August 6, 2003, with the heats staged a day earlier. Dominican Republic's Félix Sánchez set a new Pan American Games record in the final, clocking 48.19 seconds.
References
Athletics at the 2003 Pan American Games – Men's 400 metres hurdles Wikipedia(Text) CC BY-SA