The San Francisco Chronicle reports that city officials are opening their latest investigation into the company that Musk took over late last year.

That’s after the ex-employees, including a former vice president of real estate, alleged in a lawsuit filed in a federal court in Delaware that Twitter didn’t pay them promised severance. Twitter is seeking to dismiss the case.

They also allege that Musk’s team ordered numerous changes to the company’s headquarters in a 1930s Art Deco building in downtown San Francisco that violated building codes. Those changes included disabling lights and adding locks that wouldn’t open during an emergency, according to the lawsuit.

One of the plaintiffs is Tracy Hawkins, Twitter’s former vice president of real estate and workplace, who was responsible for managing the company’s physical offices and leases. The lawsuit says Hawkins wasn’t initially opposed to Musk’s takeover but “was forced to resign when Elon Musk and his transition team insisted that she violate her professional ethics by causing Twitter to intentionally breach its leases and other contracts.” The lawsuit claims Musk refused to pay rent on the building.

This is not the first time San Francisco officials have tussled with Musk, who bought Twitter for $44 billion in October and gutted much of its workforce as he converted a part of the company’s headquarters into bedrooms.

Earlier this year, San Francisco building inspectors gave Twitter’s construction contractor two weeks to submit a corrected building use permit if the company wanted to keep using two conference rooms as bedrooms.

The city launched an investigation in December after Forbes reported on the beds, prompting owner Musk to lash out at San Francisco Mayor London Breed, even though there is no evidence she was involved in the inspection.