The National Highway Traffic Safety Administration, or NHTSA, has demanded that Honda hand over documents to federal investigators who are examining the alleged problems with airbags in some Honda vehicles.

More than 10 automakers have recalled airbags in recent months that were manufactured by the Takata Corporation. While Takata sold airbags to many car manufacturers, the recall hit Honda harder than most with allegations of exploding airbags.

Allegedly, Takata airbags could violently over-inflate, which is the reason for the recall. The Takata airbags in question used a very small portion of ammonium nitrate to deploy.

It was believed that using this explosive would allow Takata to make airbags smaller and lighter. This unusual design feature actually made Takata air bags slightly more expensive, but allowed engineers to miniaturize their airbags. However, this feature may have inadvertently made the bags too powerful, allegedly causing injuries and deaths.

According to allegations of exploding airbags, the bags could deploy with enough force to cause injuries and deaths, as well as tearing and throwing metal bits from the airbag device, creating shrapnel.

NHTSA has demanded that Honda hand over documents related to communications with Takata as a part of their investigation in the matter. More specifically, the NHTSA has demanded any communications to Takata related to their airbag inflators, incident reports, pre-airbag lawsuit legal claims, warranty issues, and field reports.

Federal investigators are also grilling Honda on any possible trips by Honda’s employees to the Takata production plants in the United States and Mexico that could be relevant that may shed light on Honda’s role in the alleged airbag issues.

At present, the federal agency is considering whether or not Honda was aware of the problem prior to the airbag recall — and if the company downplayed that risk, endangering the public.

Ultimately, Honda recalled almost 10 million vehicles, including 7.6 million domestically. Honda could find itself at the center of airbag lawsuits, alongside Takata’s defective airbag lawsuits, depending on how the situation develops.

But Honda is not alone. More than 10 major car companies have employed Takata airbags since the use of ammonium nitrate in their airbags. Worldwide, more than 17 million cars have been recalled over concerns related to exploding airbags, including 11 million in the United States alone.

However, Honda is at the center of the issue, with all four known deaths allegedly linked to exploding airbags in Honda vehicles. Further, the automaker has reportedly manufactured more than half of all vehicles recalled over the issue.