Janitorial staff at Twitter's San Francisco headquarters said they were let go without notice, and one of them claimed to have heard a member of Twitter CEO Elon Musk's team claim that robots will replace them.

David Chiu, San Francisco's city prosecutor, stated that he is looking into whether Musk breached any laws, having claimed that the CEO treated former employees "like garbage."

Chiu told BBC that "Elon Musk has had a long history of flouting labor laws," adding that "while I'm not surprised this happened, I feel for these workers. We will be looking into this further."

Four cleaners who report having been dismissed from Twitter on Monday talked with the BBC and voiced their concerns. Former Twitter employee Adrianna Villarreal, who worked at the company for four years, expressed concern that she won't have enough money to feed her family over Christmas.

"It's a sad and frustrating thing for our families and children," she said.

The president of the Cleaners' Union, Olga Miranda, said they planned a walkout on Monday in protest however, they were then informed that their dismissal was effective immediately.

"They did this three weeks before Christmas," she said. "I think we were fired because we're a union."

During his ten years as a cleaner at Twitter, Julio Alvarado recalled that the atmosphere was always friendly, however, once Musk took over the company in October, things started to change.

According to Alvarado, "People worked without worries" before, but "now we are afraid." Moreover, ever since Musk bought the company, Alvarado noted that he has been escorted by private security when cleaning areas of the workplace.

"I can only tell you, I don't have money to pay the rent," the former employee highlighted, adding "I'm not going to have medical insurance. I don't know what I'm going to do."

Juana Laura Chavero Ramirez, who has worked at the company for five years before getting fired, explained that she is diabetic, and that she's concerned she won't be able to afford her medication.

"It's just horrible," she said. "We're not only losing our job, we're losing our income."

Since Monday, a small group of cleaners has demonstrated in front of the San Francisco Twitter HQ.

And on that note, Senator Scott Wiener of California told the BBC that the cleaners had been treated "horribly" by Musk's Twitter.

He then added that "in the short term, I'd like to see him [Elon Musk] treat his janitors like human beings, and get them back working - not just throw them out right before Christmas."

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