By Joe Holden

PHILADELPHIA (CBS) — On Monday night, the Philadelphia Federation of Teachers electronically filed a lawsuit against the school district over its handling of asbestos in some Philadelphia schools. The teachers’ union announced Monday they’re filing a lawsuit, days after the school district was forced to close a building that it thought had been thoroughly cleaned.

Out of words, Stefanie Marrero told the story of her three children, who are all now suffering from respiratory illnesses. She blames the environment inside Richmond Elementary.

“We were told that our school wasn’t a priority to have cleaned because the levels weren’t as high as others. But in all reality, we need our schools clean. Our children need a healthy and safe environment to learn in,” Marrero said.

The Philadelphia School District found itself on the receiving ends of a pending lawsuit by the Philadelphia Federation of Teachers. It’s a step never taken before.

“We hear over and over the district pledges to do better. I am announcing our lawsuit today as one step, to make it so,” union president Jerry Jordan said. “The district must do better.”

Since the school year began, building after building closed because of asbestos contamination. Students and teachers shifted to new locations.

The Federation of Teachers and school district last week publicly locked horns over testing results at McClure Elementary.

In the end, it was decided to keep the building closed because of asbestos. The school will remain closed for the rest of the week.

“I was asked about whether or not I trusted the process a couple of weeks ago at Carnell, and I trusted the process that had been agreed to. That process was not followed,” said Mark Paikoff, a teacher at Carnell Elementary School.

Attorney Deborah Willig says the suit seeks immediate intervention by the courts to navigate the asbestos crisis.

“It is astonishing to me they will not do what is required to protect the safety and health of 125,000 kids and 15 or 18,000 employees,” Willig said. “All they have to do is work with us.”

The school district said in a statement Monday that it would “thoroughly review” the legal filings while remaining focused on improving environmental conditions in schools.

“All of our students and staff members deserve that we stay 100% focused on our efforts to improve environmental conditions in schools. We will do just that. Our hope is that we can focus our collective efforts on finalizing the processes and protocols document we proposed to the PFT in November and genuinely working together — without distractions — to address environmental issues effectively and with the urgency our students and staff deserve. We will thoroughly review the legal filings once we receive them,” the school district said in a statement.