It’s getting to be a rough spring for Amazon as the House Committee on Oversight and Reform is now investigating the company for a spate of incidents where it put the health and safety of its employees at risk.

A letter collectively signed by several congressmen, including committee chair Carolyn B. Maloney (NY), Alexandra Ocasio-Cortez (NY), and Cori Bush (MO) stated the committee’s concern at the way Amazon has required its employees to work through dangerous conditions during a spate of natural disasters, including tornadoes and hurricanes.

The committee’s letter also called upon Amazon to furnish all relevant documents and communiques related to the way it manages its workforce in the event of a natural disaster, particularly during the most recent spate of California wildfires, the heatwave in the Pacific Northwest, as well as the time Hurricane Irma slammed into Florida.

The investigation aims to develop a solid foundation for legislative action against Amazon’s unfair labor practices while improving protective measures for the welfare of workers and mitigating the impact of climate change on workplace safety in general.

One particularly damning case is how six Amazon workers were killed in the line of duty back in December when a tornado hit an Amazon delivery station in the Illinois town of Edwardsville. The casualties were all subcontracted delivery drivers who were ordered to continue delivering parcels despite the worsening weather. It was also noted that the subcontractor’s dispatcher also failed to follow safety measures.

Last April first, just as the Oversight Committee announced the investigation, Amazon spokesperson Kelly Nantel said that the company would continue to focus on supporting employees and partners while delivering aid to the families of casualties and host communities affected by natural disasters. However, to date, it has yet to respond to the letter from Congress.

The Oversight Committee’s investigation is just the latest in a string of legislative action against the ecommerce giant. Last April ninth, the House Judiciary Committee sent a letter to US Attorney General Merrick Garland regarding how Amazon has been blocking an antitrust investigation filed against it. Committee members stated that Amazon withheld the information they requested as part of their investigation and claimed that the company is engaged in a pattern of misleading conduct to influence or impede the ongoing investigation.