Taeyeon surprised herself because of an accident she had during the Hiroshima concert of the '2013 Girls' Generation Arena Tour'!
During the "Girls & Peace" stage, all the girls went around the stage tossing baseballs to the audience. Taeyeon danced cutely along to the song, and then hurled the rubber ball as hard as she could, aiming for fans in the seats further away from the stage. However, she misjudged the angle and the ball instead went straight down, hitting a fan. She couldn't hide her surprise and embarrassment and ran away to the center of the stage, hiding behind the ball case.
The other girls gathered when they realized something was wrong, and the music was muted as Taeyeon explained herself and asked the fan if they were OK.
Check out her cute mistake below!