CHICAGO (CBS) The fight over the field house at Whittier Elementary School in the Pilsen neighborhood is about to get worse.

Parents at Whittier have taken over the school field house and have been living in it for 20 days, but now Chicago Public Schools has had the gas supply to the building shut off.

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CBS 2’s Mai Martinez reports.

CPS says the building is not structurally sound and they asked for gas to be cut off because of safety concerns. People inside the field house say the school system is just trying to force them out by making conditions more difficult.

Crews from Peoples Gas shut off the gas supply to the field house at Whittier around 8:40 a.m. Monday. The parents holed up inside say the gas is used to heat the building and water, and they say there’s only one reason Chicago Public Schools ordered it shut off.

“Intimidation. I mean, they’ve done it before,” Laura Ramirez said.

CPS says the gas disconnection was prompted by safety concerns about the “increased number of children, adults and combustible materials inside a structure.”

According to CPS, those combustible materials include hundreds of books which have been donated for a makeshift library inside the field house. But some parents question the rationale behind the move.

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“They want us out because it’s unsafe, but yet they make it even unsafer,” said Ramirez who is now concerned electricity and water to the building may also soon be shut off. “They’re ruthless, and I do not put it past them.”

Another parent, Manuel Beltran is equally concerned.

“They want us to run away, but we’re not going to run away. We’re going to step up here,” he said.

Beltran and the rest of the parents and community members staying in the field house around the clock say they’re determined to stay because they want the field house converted into a real library for their children.

They’ve been fighting for that by refusing to leave the building for nearly three weeks and pleading their case to everyone they can. Monday, it was potential mayoral candidate Rahm Emanuel. Emanuel took down a number from the group, but members say they felt their cries for help fell on deaf ears.

Instead of focusing on the setbacks, they’re celebrating their victories, including their little library, which opened last week.

“That’s what we’re fighting for so we’re staying here, and we’re not going nowhere until they confront us,” said Beltran. “They can cut any utility. We’re going to be here.”

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Members of the group say they plan to stay in the field house until CPS CEO Ron Huberman agrees to meet with them, but CPS spokeswoman Monique Bond says that meeting won’t happen until the group leaves the field house.