Mary Gundel, a former Dollar General store manager, recently went viral after posting a series of videos on TikTok explaining how the job ran her and her employees into the ground.

It seems Sen. Patty Murray was a fan of Gundel’s work.

The Democrat from Washington state sent a pair of letters Friday to the chief executives of Dollar General and Dollar Tree, the country’s two dollar-store behemoths, pillorying the companies for the working conditions in their stores.

Murray, who chairs the U.S. Senate Committee on Health, Education, Labor and Pensions, asked that the two companies turn over a slew of records related to job titles, wage rates, meal and rest breaks and sanitation and workplace safety inspections.

“[B]oth Dollar Tree and Family Dollar stores have seen explosive — and continuing — growth,” Murray wrote the retailers in her letters. “I call on you to explain [your company’s] shameful labor practices and commit to improving conditions for workers moving forward.”

Dollar General couldn’t immediately be reached for comment. A spokesperson for Dollar Tree said the company hadn’t read the letter yet and wasn’t prepared to comment as of this posting. Murray’s office just sent the letters Friday afternoon.

“While Dollar General’s employees struggle to make ends meet, your own compensation as CEO was a staggering 986 times greater than the median employee’s annual earnings.”

– Sen. Patty Murray to Dollar General CEO Todd Vasos

The country’s dollar stores have long been known for lawsuits alleging minimum wage and overtime violations, and more recently citations showing workplace safety violations. As HuffPost chronicled in 2013, the stores tend to operate on tight payrolls, with salaried managers often working 60- or 70-hour weeks and handling non-managerial jobs, like unloading trucks and stocking shelves.

In her letter to Dollar General, Murray accused CEO Todd Vasos of growing rich while his employees struggled.

“While Dollar General’s employees struggle to make ends meet, your own compensation as CEO was a staggering 986 times greater than the median employee’s annual earnings,” she wrote, referencing the company’s financial filings. “A 986:1 ratio of CEO to median employee compensation is nearly three times the average ratio of other major corporations in the United States.”

She also noted recent citations against both Dollar General and Dollar Tree by the Occupational Safety and Health Administration. OSHA said earlier this year that the penalties against Dollar Tree over the past five years have amounted to more than $9.3 million, due to blocked exits, fire hazards and other dangers.

Dollar stores have been growing rapidly in recent years, undercutting local independent stores and helping to transform the retail landscape. Nearly half of all retail locations opened last year were projected to be dollar stores.

Given their expansion, Murray called on the companies to “commit to improving conditions for workers moving forward.”

In one of her viral Dollar General videos, Gundel showed off the hard-working employees at her Tampa, Florida, store, as well as some of the challenges they face. She filmed cart after cart of unboxed product stretching through an aisle in the store, saying it was stuck there because the back room couldn’t hold it.

“They can’t fit carts down the aisle,” she said of her customers. “I will not run a location like that.”

Gundel was fired earlier this month.

“I wasn’t afraid of losing my job,” she told The New York Times. “I was not going to be silenced.”