For many of us, Amazon is one of the websites we turn to when we need pretty much anything. They sell everything from books and toys to food and electronics. It’s more diverse than a department store, and the prices are often very competitive. It’s also very convenient to have products shipped directly to your door.

Amazon Prime members get even more perks than regular Amazon shoppers. It starts with free 2-day delivery, but there’s photo storage, video streaming, music streaming and more. Once you go Prime, it can be hard to even consider going back to the free version of Amazon.

While customers are pretty happy with the company, many employees are not. Some warehouse employees claim they work long shifts for little pay and are fired if they can’t keep up with the demanded pace. It turns out there is a negative side to fast and free shipping.

Amazon doesn’t want employees to unionize. Meanwhile, during Prime week, some Amazon employees walked off the job in protest. Now, authorities are getting involved.

Nicholas Biase, a spokesman for the U.S. Attorney’s Office for the Southern District of New York told ABC News, “This morning, the United States Department of Labor’s Occupational Safety and Health Administration entered Amazon warehouses outside New York City, Chicago and Orlando to conduct workplace safety inspections in response to referrals received from the United States Attorney’s Office for the Southern District of New York concerning potential workplace hazards related, among other things, to Amazon’s required pace of work for its warehouse employees.” He added, “The Civil Division of the SDNY is investigating potential worker safety hazards at Amazon warehouses across the country, as well as possible fraudulent conduct designed to hide injuries from OSHA and others.”

Watch the video below to hear more about this investigation into worker conditions at Amazon warehouses and to hear from some Amazon employees what it’s really like to work at the warehouses.