An on-duty firefighter was punched several times while responding to a domestic-related incident on the South Side, according to Chicago police. The attack occurred Wednesday morning in the Auburn Gresham neighborhood near the 8300 block of S. Racine. Chicago police said a 25-year-old man punched the firefighter several times. The firefighter was transported to a local hospital in stable condition. The offender is in custody, according to police.