A Cook County public guardian is suing a state contractor for negligence on behalf of two children who were sexually abused by a caregiver the agency was supposed to monitor.

The lawsuit, filed Tuesday in Cook County Circuit Court on behalf of two children identified as A.W. and K.W., accuses the child welfare agency Children’s Home + Aid of failing to monitor the children while they were in the care of Eric Nichols, according to court documents.

The suit also seeks damages against Nichols for sexually abusing the two children.

A.W., then 8 years old, and K.W., 2, were siblings brought to the attention of the Department of Children and Family Services in December 2011, according to the suit. The siblings’ mother, who was accused of neglect and of abusing drugs, agreed to relinquish custody.

Their mother told DCFS that Nichols was A.W.’s father and refused to identify the father of K.W., according to the suit. A DCFS investigator spoke to Nichols, who agreed to take custody of the children. A paternity test would later find that Nichols was not the father of A.W.

DCFS contracted with Children’s Home + Aid in December 2011 to monitor the children while they were in his care.

While in Nichols’ care, both children were sexually abused by him, according to the suit. He pleaded guilty on Aug. 6, 2014 to predatory criminal sexual abuse and was sentenced to two 15-year prison terms to be served consecutively.

According to the suit, DCFS assigned Children’s Home + Aid to monitor the children, follow the DCFS safety plan and provide social services to the family and Nichols. Because Nichols was an unlicensed caregiver, the agency’s case workers were required to visit the home at least two times each month.

The suit claims caseworkers only visited the home once in January, February, March, May and July of 2012. Case workers did not visit the children in either August or September that year. Further, the agency failed to follow up on the children’s mother’s concerns during visits and “did not explore alternate placement” when she asked that the children be placed with her sister.

Children’s Home + Aid case workers “ignored or failed to appreciate the obvious red flags raised by Mr. Nichols’s unsuitable housing and homelessness” that included the children living in one home described as “unsafe and dirty” and having “not enough bedding,” according to the suit. Between December 2011 and June 2012 Nichols and the children moved “at least six or seven times” and A.W. missed the entire 2011-2012 school year due to frequent moving and homelessness.

A court report written by Children’s Home + Aid employees  said K.W. was “thriving” in her placement with Nichols, the suit says. When a juvenile court ordered K.W. removed from the home, Children’s Home + Aid took 11 days to comply. A.W. remained in Nichols’ care.

In February 2013, the sexual abuse allegations against Nichols began to come to light, according to the suit. A DCFS investigation into Nichols was launched at the end of 2013 and he was arrested on abuse allegations in January 2014.

The suit seeks unspecified damages from Children’s Home + Aid for a count of negligence on behalf of each child, according to the suit. An unspecified amount is also sought for willful and wanton misconduct for each child from Nichols.

A spokesman for Children’s Home + Aid said the agency could not comment on the case pending litigation.