CHICAGO (CBS) — A Wilmington couple is suing a southwest suburban school district because their 10-year-old daughter was humiliated on a field trip last January when teachers allegedly refused to stop for a bathroom break and forced her to urinate in a cup on a moving school bus.

Todd and Lisa Holmes filed the emotional distress lawsuit Tuesday against Wilmington School District 209U, Supt. Jay Plese and Wilmington Middle School, among others.

“Obviously the parents are very distraught and upset that this happened,” said the family’s attorney, Telly Nakos. “They entrust the parents and the teachers and the chaperones on the field trip to provide a safe environment for the children and what occurred was just outrageous.”