CHICAGO (AP) — Several members of Congress want Amazon to explain why an Illinois warehouse that collapsed during a 2021 tornado, killing six employees, is being rebuilt without adding upgraded storm shelters.

In a letter released publicly Thursday, U.S. Representatives Cori Bush of Missouri, Alexandria Ocasio-Cortez of New York and Sen. Elizabeth Warren of Massachusetts said the e-commerce giant “has a responsibility to make the modest investments” and suggested the company was “putting your profits over workers’ safety.”

Amazon’s severe weather policies have been under scrutiny since the December 2021 disaster. Federal safety investigators later found that some workers at the warehouse weren’t aware that a restroom in the northern portion of the building was the designated tornado shelter and instead went into a restroom in the building’s south end, where the collapse occurred.

“Amazon has a responsibility to make the modest investments necessary to ensure that workers in its Edwardsville facility are protected from future disasters,” the letter addressed to Amazon CEO Andy Jassy said.

The letter released by the three Democrats cited St. Louis-based KSDK-TV ‘s reporting on plans to rebuild the facility back to “pre-loss conditions,” based on a permit issued by the city of Edwardsville and obtained through open records laws.

Amazon representatives did not immediately reply to email messages seeking comment Thursday.

“The landlord is required to return the building to its pre-condition state, and that’s what they’re doing,” Nantel said.

U.S. regulators in April told the Seattle-based company that inspectors found the company’s procedures met federal safety guidelines for storm sheltering. The Occupational Safety and Health Administration did advise Amazon could do more to protect workers and contract employees, including ensuring that employees participate in emergency weather drills.

Amazon did not face any fines or penalties.

In their letter, Bush, Ocasio-Cortez and Warren said the OSHA findings on improved severe weather planning and training should be followed. They also acknowledged a previous written response from Amazon noting that federal law doesn’t require storm shelters.

But the trio wants Amazon to go further and incorporate a shelter into the Edwardsville warehouse. They asked the company to respond by mid-January.

“We urge you to revise your approach to ensure that such a tragedy never happens again,” the letter said.