After millions of dollars in renovations, some parents claim McKinley Tech High School still suffers a critical shortage of teachers.

"We asked what's going on, why there's no teachers," said Monica Lowe. "They made false promises."

Her son is a junior at McKinley. After weeks of school, his Algebra II/Trigonometry class is on its second substitute teacher, she says.

"Parent-teacher conference is next Friday, October the third, Mr. Ford, and we have yet to receive a teacher," Lowe told ABC 7/NewsChannel 8 reporter Sam Ford Friday.

McKinley's not alone. ABC 7/NewsChannel 8 visited Thurgood Marshall Elementary School last week and found classes with only substitute teachers. One classroom with a permanent teacher had 46 students.

The teachers' union blames schools Chancellor Michelle Rhee.

"The chancellor was able to fire 270 teachers this summer without any problem, but yet has not been able to get a teacher in every classroom now that it's the fifth week of school," said teachers' union spokesperson George Parker.

The union provided ABC 7/NewsChannel 8 with what it said is an an internal, school-system list of classrooms with no permanent teacher. There were 91 classes on the list as of Thursday.

Among the vacant positions on the list, a math teacher at McKinley High School.

The union says many of the teachers who were fired were a point or two from certification. They've been replaced by substitutes, said Parker.

Parents like Monica Lowe say they won't put up with it.

"I refuse as a parent to allow my son or any of the children to suffer," she said. "[T]hey just blow us off as parents as if we're not important."

ABC 7/NewsChannel 8 contacted the school system to ask about the list provided by the union and parents' concerns. A spokesperson had not called us back as of Friday evening.