(CNN) The teenage girl screamed and fought with the school security officer when he tried to check her bag.

"The police later told me she had dirty clothes in her bag because she was homeless and didn't want anyone to know," Akbar Cook, the principal of West Side High School in Newark, New Jersey, told CNN. "She was fighting for her pride."

Cook said many students at West Side faced humiliation because they didn't have anything clean to wear.

So when school starts September 4, there will be a new facility in the building: a free laundromat.

Shame keeps students away

Kids who could not afford to wash their clothes faced intense teasing when they showed up in dirty outfits. Classmates sometimes snapped photos and tagged the students on social media.

"I've seen a few kids in the back of the class talk about one of the people in front of the class and how they smelled and how their clothes looked dirty," student Nasirr Cameron told CNN affiliate WCBS.

Cook heard the students talking, too. He saw the posts and quickly suspected that the bullying was a top reason why 85% of his students chronically missed school.

"These are kids, good kids who want to learn, that are missing three to five days a month because they were being bullied because they were dirty," Cook explained to CNN. "I even changed the school uniform to darker colors so they could go more days without cleaning them, but even with that, students were struggling to have them look clean enough to attend."

So two years ago, the principal applied for a grant from a foundation associated with one of Newark's main utility companies, PSE&G. He received $20,000 to turn an old football locker room into a school laundromat.

A clean start to the school year

The renovations are now complete. The room has five washers, five dryers and a growing stock of detergent donated from around the country.

Student Rah-Asia Marrow stocks the shelves with donated laundry detergent for the student laundromat at West Side High School.

"As the story has spread, we have been receiving packages of detergent at the school and through our Amazon wish list page ," Nicole Daniel, the school's operating assistant, told CNN.

School social worker Jamila Hammond told WCBS it feels good to know that they can help students who wanted to go to school but felt disgraced by their clothing.

"Many times the students may come in because they're embarrassed, they don't look the same, somebody's complaining about a body odor. I would say, 'OK, baby, then we're going to have to do it the old way.' We have soap, we have water. But now with this laundry room we don't have to do that," Daniel said.

The room is open to students free of charge between 3 p.m. and 6 p.m. An adult supervisor keeps an eye out during those hours and helps pass on the important life skill of being self-reliant; one scoop of detergent and one measure of dignity at a time.

Principal Akbar Cook poses with a few of the graduating students of the West Side High School class of 2018.

"We are trying to teach them to navigate their pride," Cook said. "My kids are fighters -- they just need good ways to fight for themselves, and then take pride in what they can do."