Chanting "make them pay" and other rallying cries, thousands of hotel workers continued their strike Tuesday, after contract negotiations failed between the UNITE HERE labor union and some of the nation's largest hotel chains.

Some 15,000 workers ranging from front desk clerks to back of house laundry staff are demanding higher wages, better workloads and a return to pre-pandemic staffing at various Hilton, Hyatt, Marriott and Omni hotels.

"We are the reason why the hotel is open 24/7," Aissata Seck, a union member and banquet server at the Hilton Boston Park Plaza, told USA TODAY. "We are everything for the hotel to be a business today."

But many workers say they can't afford to live in the cities they welcome guests to, though hotels assert otherwise.

Why are hotel workers striking?

The pandemic took a huge toll on the hotel industry, and many hotels responded by cutting staff and guest services like housekeeping and room service. Guest occupancy has since bounced back, but the union says staffing has not.

"They cut down a lot of shifts and positions – like housemen to help us – and try to cut down our schedule, try to make us on call and as much as they can, try to save money for themselves," Afong Lam, a union member and room attendant at the Westin St. Francis in San Francisco, told USA TODAY. Westin is part of the Marriott family of hotels.

Lam said housemen previously took care of things like vacuuming carpets and cleaning bathrooms, which she now does on top of her existing duties.

"Everybody has pains now because of extra workload," she said. "If you work every day like this, then you will get exhausted all day, and then when you go home, you don't feel like doing anything."

But with the cost of housing in the Bay Area, she says she can't afford to miss work or call in sick. The same goes for Seck around Boston.

"Before pandemic, I used to pay $1,900," Seck recalled. "After pandemic, now I'm paying $3,000."

That's more than she can afford on her hotel wages, so she drives for Uber and braids hair on the side to supplement her income. She would love to be able to live off her job at the hotel.

"It's harder and harder," she said. "You have to do more work, then less money."

"Since COVID, the hotels have rebounded, but wages have not caught up," Gwen Mills, international president of UNITE HERE, told USA TODAY before contracts expired at the end of August. "We need wages to catch up so one job can be enough."

In a statement to USA TODAY, Michael D’Angelo, head of labor relations – Americas, Hyatt, said:

"We have a history of offering competitive wages and benefits in each market, including comprehensive health care at little to no cost, as well as retirement savings. We have offered competitive wages, health care and retirement benefits at the hotels that are on strike at this time, and colleague benefits and wages remain unchanged as we negotiate a new agreement."

How does housekeeping at hotels work?Here's what is happening behind the scenes.

Which hotels are impacted?

Workers at more than 65 hotels across the country have authorized strikes in cities like Baltimore, Honolulu, San Diego and Seattle. Not everyone has actually gone on strike. For instance, there haven't been any strikes at Omni hotels, like there have been at Hilton, Hyatt and Marriott properties and the Fairmont Copley Plaza in Boston. There were nearly 10,000 workers still striking Tuesday.

Lam is hopeful.

"We hope the manager will be on our side, you know, to think of us, because it's not easy to be working like this every day," she said. "We hope the manager can understand."

"Our colleagues are the heart of our business, and Hyatt has a long history of cooperation with the unions that represent our employees, including UNITE HERE. We are disappointed that UNITE HERE has chosen to strike while Hyatt remains willing to continue bargaining in good faith," D'Angelo said. "We look forward to continuing to negotiate fair contracts and recognize the contributions of Hyatt employees."

Similarly, a Hilton spokesperson told USA TODAY: "Hilton makes every effort to maintain a cooperative and productive relationship with the unions that represent some of our team members, and we remain committed to negotiating in good faith to reach fair and reasonable agreements that are beneficial to both our valued team members and to our hotels."

Marriott and Omni did not immediately respond to USA TODAY's requests for comment.

How long will the hotel strikes last?

The current round of strikes is limited to up to three days ending Tuesday, but future strikes are possible if parties remain far apart in negotiations.

"They need to sign the contract before we move on and fight again, because the fight will never stop. Every single step, you have to fight for it," Seck said.

What should guests expect?

Both Hilton and Hyatt have contingency plans to keep operations running.

UNITE HERE is directing guests to Fairhotel.org to look for hotels not impacted by potential strikes.

Contributing: Kathleen Wong, USA TODAY