Amazon’s warehouse culture is making headlines again this week after a nonprofit news organization obtained injury records from 23 of the company’s fulfillment centers.

Reveal, a project of the Center for Investigative Reporting, discovered that serious injuries are much higher at Amazon facilities than national averages. Injuries are particularly prevalent during peak shopping periods, such as the upcoming consumer holidays Black Friday and Cyber Monday.

The findings: The rate of serious injuries at the Amazon warehouses in the investigation was more than double the national average for the industry. Reveal discovered an injury rate of 9.6 for every 100 full-time warehouse workers in 2018, compared to the national average of four. At Amazon’s Kent, Wash., facility — a key warehouse near the company’s Seattle headquarters — the injury rate was even higher. There were 13 injuries per 100 workers last year, according to Reveal. At one Oregon facility, the number was 26.

Reveal’s investigation includes allegations that Indiana officials downplayed Amazon’s responsibility in a warehouse worker’s death because Indianapolis was in the running for the company’s coveted second headquarters at the time. Amazon declined to comment on the Indiana case, citing privacy concerns.

Background: Amazon has been investing heavily in super-fast shipping, shifting the core perk for Prime members from two-day deliveries to one-day. The company’s logistics engine often ferries items to customers’ doors within hours of a purchase. Pressure to increase speed and efficiency has led to reports that detail a hard-charging culture inside Amazon warehouses. Amazon said in its most recent earnings report that it will invest nearly $1.5 billion in the fourth quarter alone for its one-day shipping initiative. The company is setting new industry standards as competitors narrow their delivery wait times to keep up.

What Amazon says: A spokesperson told Reveal the injury numbers are higher than competitors because Amazon keeps meticulous records to protect worker safety. Amazon provided this statement to GeekWire in response to the investigation:

“Reveal is on to something and it’s something OSHA has been talking about for years: there’s a dramatic level of under-recording of safety incidents across the industry – we recognized this in 2016 and began to take an aggressive stance on recording injuries no matter how big or small. We believe so strongly in the environment that we offer for fulfillment center employees, including our safety culture, that we offer public tours where anyone can come for themselves one of our sites firsthand. Come see for yourself the focus on safety we have in our buildings.”

Why it matters: Injuries increased on Amazon shopping holidays like Cyber Monday and Prime Day, according to the investigation. As the biggest shopping weekend of the year approaches, treatment of Amazon employees are under a microscope. Activists and regulators are taking note of labor practices inside Amazon warehouses amid broader scrutiny of Big Tech.

Yes, but: Reveal is not the first to report on the strenuous work environment inside Amazon fulfillment centers. So far, the negative coverage doesn’t appear to influence consumers. Last year the five-day shopping period over Thanksgiving weekend was Amazon’s biggest shopping event so far, based on the total number of products ordered worldwide.

Go deeper: Read Reveal’s in-depth coverage of warehouse worker injuries here.