(AP) - A New York City grade school teacher was arrested Thursday on charges he inappropriately touched a student, marking the third time this month a public school employee has been accused of abusing children. Wilbert Cortez, 49, was in custody awaiting arraignment on charges of sexual conduct against a child and endangering the welfare of a child. The name of his attorney was not immediately available. According to a letter sent to parents, Public School 174 in Queens first learned last October Wilbert "might have inappropriately touched a student at our school." The school alerted authorities and reassigned the teacher "to a central office away from students," it said. Schools Chancellor Dennis Walcott said he was "appalled" by the charges. "No adult who inappropriately touches a student, in or out of school, belongs anywhere near the children we are responsible for protecting," Walcott said in a statement. "I will do everything in my power to ensure that individuals like Mr. Cortez can be swiftly removed from our classrooms as soon as allegations surface, and be barred from teaching in our schools if those charges are substantiated." Cortez has been a teacher at the school since 2000. He started with the Department of Education as a substitute teacher in 1986. The latest case follows the arrests earlier this month of employees at two other elementary schools. In the first case, a teacher's aide was jailed on charges he videotaped himself spanking one naked child and fondling another in a classroom at a Brooklyn school. An FBI investigation uncovered the videos on a computer seized from his home, authorities said. Another aide at a Manhattan school was arrested three days later on sexual abuse and other charges accusing him of taking a boy to a school bathroom and having the child undress in a stall.FBI urges victims to come forward after teacher's aide arrestTeacher's aide arrested for allegedly possessing, making child porn