NEW YORK (CBSNewYork) – Two more subway trains have been vandalized in a crime spree that is already costing the MTA hundreds of thousands of dollars to repair smashed windows, the transit agency said Saturday.

On Friday night, 21 windows were broken on two 7 trains, which cost the MTA $10,000 to fix.

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More than 400 windows have been smashed in recent months, especially on the 7, 2, and 3 subway lines, CBS2’s Christina Fan reported Saturday.

“We’re challenged financially. So, it’s a big deal to us. It should be a big deal for everybody in New York too, because this is your money,” said MTA Chief Safety and Security Officer Patrick Warren.

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The bill to repair the windows is $300,000 and counting.

Commuters are hoping the MTA doesn’t raise fees to cover the cost.

“The city is already losing a lot of money because of COVID, so it’s kind of sad that people are going around doing that,” Fazya Bacchus said.

“That’s just going to end up being bad for everybody, you know?” another commuter said.

Officials still don’t know if it’s one person or many people committing these crimes, and they’re still trying to figure out a motive.

Watch Christina Fan’s report —

Subway windows are much thicker than ones generally installed at homes. That’s why the MTA believes those responsible use a hammer, pipe or blunt object and commit the crimes inside the car while it’s in motion.

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The agency also hopes witnesses come forward with information.

Commuters say it’s senseless.

“There’s a lot of things happening. This is just one more thing that I think New Yorkers would have to think about, and it’s kinda scary,” said Salima Koroma, of Harlem.

“I think it’s pointless, you know what I mean? It’s causing damages to your city,” one man said.

“I don’t know if that’s someone’s idea of, like, relieving stress, it’s really messed up,” said Sabrina Sesay, of Bed-Stuy.

“I think it’s boredom for our teenagers. This is their way of acting out,” said Ann Spreeman.

“The 7 train, I feel like, is actually one of the rougher trains out of the ones in Queens because there’s so much graffiti and the broken glass windows,” said Rachel Tyo.

RELATED STORY: NYPD Says Vandal Has Smashed Subway Windows 63 Times; Official Calls Is ‘Criminal, Dangerous, Despicable’

Federal regulations will not allow train cars to run without the windows in tact. So, with each incident, trains have to be taken out of service.

“We are at the, our stock piles are depleted. We are now, to keep up with this … It’s the supply chain, if they can keep up, then we can keep up, so we’re at that point now. We’re only as good as supply chain. We have yet had to pull trains out of service for extended periods of time, but that’s certainly a possibility going forward,” Warren said.

So far, the vandalism has not caused too many disruptions to riders, but that could change. A damaged window could take up to three hours to fix, CBS2’s John Dias reports.

“It could make your commute a little bit longer, while you wait for a second train… It presents the opportunity for more crowding because we have less trains on the line,” said Warren.

Earlier this month, police shared surveillance video of a man they said smashed subway windows 63 times. He has not been arrested and police continue to investigate other cases.

Officials said they hope more awareness about the vandalism helps prevent future problems.

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